The Boy Allies Under the Seaby Robert L. Drake

"What I would like to know," said Frank Chadwick, "is just how long England intends to put up with the activities of the German submarines in the waters surrounding the British Isles."

"How long?" echoed Jack Templeton. "Surely you know that England is already conducting a vigorous campaign against them."

"I don't seem to have heard anything of such a campaign," returned Frank dryly; "but another big liner was torpedoed and sunk off the coast of Ireland yesterday. What are we going to do about it? That's what I want to know."

"I'll tell you a little something you don't seem to know," said Jack. "In the last thirty days, in the neighborhood of a hundred German submarines have disappeared—sunk or captured—no one seems to know which. Nevertheless, it is a fact. Through diplomatic channels word has been received in London that a large number have failed to return to their bases. The German government is much disturbed."

"Where have they gone?" asked Frank, with some surprise.

"I don't know. Nobody knows—unless, perhaps, a few high government officials. They have just naturally disappeared—vanished."

"How do you know all this?"

"I happened to hear Lord Hastings discussing it with Mr. Churchill while you were out the other day."

"But, of course, Mr. Churchill knows what has happened to the submarines."

"Of course; but he's not telling everything he knows."

"But doesn't Lord Hastings know?"

"I suppose so; but he is keeping his information to himself."

"Well, I didn't know any of them had disappeared."

"They have, though, and I heard Mr. Churchill say that the government hoped within another month to have rid British waters entirely of the German submersibles."

"I hope his hope comes true," said Frank with a smile.

"And I; but I would like to know something more of the mystery of these vanishing submarines."

Both lads were to learn something more, even sooner than they could possibly have hoped.

The door opened and a man strode into the room. Attired in the full uniform of a British naval commander, he made a striking appearance in his gold and lace. He greeted the two lads with a smile.

"Well, boys?" he said.

The newcomer was Lord Hastings, erstwhile distinguished secret service agent and new commander in his British majesty's royal navy. Also, though the fact was known to few, he was a distant cousin of the king himself and one of the most highly trusted officers of the empire.

"Well, boys?" he repeated.

"Well, sir," said Frank, "we were just discussing the mystery of the vanishing submarines."

Lord Hastings gazed at the lad in surprise.

"Vanishing submarines!" he repeated. "And tell me, how did you know there were such things as vanishing submarines?"

"Why, Jack told me, sir," replied Frank.

"And how did you know it?" demanded Lord Hastings of Jack.

"I heard you and Mr. Churchill discussing it, sir," replied Jack.

Lord Hastings drew a long breath, evidently of relief.

"I didn't know we had been so indiscreet," he said, half to himself. "However, there is no harm done, for I know you boys are to be trusted not to repeat what you overhear. I'll tell you this, you two are among the very few who know that any of the German submarines have been accounted for."

"Then it is true?" asked Frank.

"Oh, it's true enough," replied Lord Hastings. "Perhaps a hundred of them have disappeared."

"And where are they, sir?" asked Frank. "At the bottom?"

"That," said Lord Hastings with a slow smile, "is the mystery the German government would like to solve."

"But surely you know, sir."

"If I did, I would not repeat it within these four walls," declared Lord Hastings. "Walls have ears, you know, as is proven by the fact that Jack overheard my conversation with Mr. Churchill."

"I didn't mean to listen, sir," interrupted Jack.

"Oh, I know that," replied Lord Hastings. "But now take my advice, and keep what you know locked close within you."

"We shall, sir," replied both lads.

"Good! Now I have a piece of news for you."

The two lads stepped forward eagerly.

"Are we to go on active service again, sir?" asked Frank anxiously.

"It's about time we did," mumbled Jack, half to himself.

Lord Hastings smiled as he saw the eager looks upon the faces of both.

"Well, we have a little work cut out for us," he replied quietly.

"Hooray!" cried Frank.

A pleased expression fluttered across Jack's face, but he gave voice to no exclamation; he was never as effusive as his chum.

"I'm glad you're pleased," returned Lord Hastings. "Yes, we shall see active service, at once."

"When do we start, sir?" asked Frank, his face shining.

"In the morning."

Frank's face fell.

"I was in hopes it was to-night," he replied.

"Scouting, submarine or what?" demanded Jack.

"You will have to wait for an answer to that question," said Lord Hastings. "In the meantime, it would be well this afternoon to get whatever equipment you may need. Your other things, together with mine, are at the bottom of the sea with the old D-16."

"And perhaps," said Frank slyly, glancing at Lord Hastings, "before our present work is over we may know something of the mystery"—he lowered his voice—"of the vanishing submarines."

Lord Hastings eyed him somewhat coldly.

"Perhaps," he said, and, turning on his heel, left the room.

"You shouldn't have said that, Frank," declared Jack, when they were left alone. "You remember what he said about the walls having ears."

"I know it," said Frank, with sincere regret. "It just slipped out."

"If you'll take my advice, you'll see that it doesn't slip out again," advised Jack.

"I'll be mum from now on," said his chum with a slight smile. "But now I guess we may as well get what things we may need."

"All right," said Jack.

They picked up their caps and made their way from the house.

And while they are engaged in the task of out-fitting themselves for the coming expedition, a few words concerning the two chums may well be written.

Jack Templeton was an English boy some eighteen years of age. Born in the British Isles, he had nevertheless spent most of his life in Africa, his father having conducted a small trading station upon the coast of that continent. Jack's father was a scholar and from him the boy had acquired a good education.

Jack's father died, leaving the boy as a legacy nothing but the little African trading store; and Jack set about to make his own living there and to put by enough so that within a few years he would be able to return to the land of his birth.

And then fate took a hand in shaping his career.

A party from a passing schooner stopped for supplies at Jack's store, and, in the lad's absence, departed without paying for the provisions. Jack set forth to collect. He climbed aboard the schooner before it hove anchor, and, payment being refused by the schooner's crew, a fight ensued.

Jack was forced to take refuge in the hold, while the ship got under way. He succeeded in making his way to the next compartment, where he was surprised to find two other prisoners. These he released, and they proved to be a British secret service agent and Frank Chadwick.

Frank was an American boy. He had been separated from his father, and while seeking him in Naples had been shanghaied aboard the schooner, and there he was, following a mutiny among the crew, as Jack found him. By some resourcefulness and not a little fighting, the lads overcame the crew and made their way back to Jack's home, taking the other prisoner with them.

Here they joined an expedition in which the secret service agent was implicated, and in this manner met Lord Hastings. The latter took an interest in them at once, and, after they had proved their mettle, the British nobleman took them aboard his own vessel as midshipmen.

Then followed a series of exciting adventures, which had led them to many parts of the world. They had been instrumental in the first big victory of the British fleet off Heligoland; they had taken part in the pursuit of the German cruiser Emden, "the terror of the seas," and had been in at the death; they had been with the British fleet that had sunk the last German squadron upon the oceans—off the Falkland Islands; they had taken part in many and dangerous other exploits, having more than once been in the heart of the enemy's territory; and always they had returned safely.

But there was once when it seemed that all—Lord Hastings, Frank and Jack—had come to their end. It came about in this wise: After a long cruise, which resulted in great successes, their submarine, D-16, had come to grief in the Dardanelles. They were caught below and it seemed that all must perish.

Then Jack had decided that it was futile for all to die; there was safety for all but one. A deck of cards decided who was to stay, and Jack had drawn the fatal card—the ace of spades.

Officers and crew were launched to safety by means of a torpedo tube; and Jack sat down to await the end. But, in some unaccountable manner, the submarine had suddenly risen to the surface, and Jack, taking advantage of the single instant the vessel was above water before it took its final death plunge, flung himself clear. And thus all were saved.

But, because of their desperate experiences, they were unfit to immediately resume new duties; so all had returned to England until such time as they would be physically in shape again.

Now Jack Templeton, although young in years, was wise in the ways of the world. Also he was of huge stature and as strong as an ox, as he had proved more than once when put to the test. Frank, although by no means as large as his chum, was sturdy and strong, and able to give a good account of himself when occasion required.

The one noticeable difference between the two was that Frank was high-tempered and quick, whereas Jack was always cool and collected. And this very fact had more than once showed that Jack, while not exactly more dependable, could always be relied upon to keep his head.

While both were skillful in the use of weapons, here was a place where Frank excelled. He was a dead shot with rifle or revolver and was a strong swordsman. Jack was a good shot himself and a skillful fencer, but he was not in Frank's class when it came to the use of sword or firearms.

Upon their last expedition Jack and Frank had acted as first and second officers respectively of the submarine, and both now held the rank of first lieutenant. Their promotions had come deservedly. They had the implicit confidence of Lord Hastings and more than once had offered valuable advice, which Lord Hastings had acted upon.

Now a few words about the progress of the war. The seven seas had for some time, save for the presence of the German submarines, been swept clear of German, Austrian and Turkish fighting ships. Not a one remained at large to prey upon the shipping of the Allies. The real fighting strength of the navies of the three central powers still remained in their own fortified bases, well guarded by mines.

The Allies had established such an effective blockade that none dared to venture forth. So the naval situation was practically at a standstill, where indications pointed to its remaining until the main German fleet, bottled up in Heligoland, and the main Austrian fleet in the Adriatic should summon sufficient courage to sally forth and give battle; and there had been nothing to indicate any sudden action on the part of either.

On several occasions British submarines had penetrated the mine fields and created considerable havoc, and aircraft had dropped bombs from the air. But along these lines the German submarines had been more successful and now were the one real menace confronting the naval supremacy of the Entente powers.

Hundreds of ships, large and small, had fallen easy prey to these under-sea terrors. Big ocean liners, crowded with passengers, non-combatants, had been sent to the bottom with terrible loss of innocent lives. Chief among these tragedies laid to the door of the German submarines was the sinking of the Cunard liner Lusitania, in which more than a thousand men, women and children had been drowned.

And, so far as the British public knew, England had taken no steps to combat this under-sea peril. However, as Lord Hastings had told the boys at the opening of this story, Great Britain had taken such steps, and that they were effective was evident from his additional statement that in the neighborhood of a hundred submarines had "vanished."

But this warfare was not to end until the submarine evil had been eradicated. The German under-sea craft must be disposed of so effectively as to preclude further danger to British shipping. And it was in this work that Jack and Frank were soon to play a prominent part.

CHAPTER II.

ON ACTIVE SERVICE AGAIN.

For some reason unknown to Jack and Frank, when morning came, Lord Hastings announced that the start would not be made until after nightfall, at which both lads showed keen disappointment.

"I'll tell you what you can do," said Lord Hastings. "I'll give you an order for my motorboat and you can go to Gravesend during the day if you care to. I'll meet you there at the Lion Inn to-night at 10 o'clock."

Frank was delighted.

"That's better than hanging around here all day, waiting for night to come," he said. "What do you say, Jack?"

"Anything to humor you," replied the latter with a smile.

"Take all your things with you," said Lord Hastings; "and, above all, hang on to that motorboat. Don't let anybody get it away from you."

"We'll hang on to it, never fear," replied Frank. "Come on, Jack."

"Wait a minute," ordered Lord Hastings. "You'll need this written order to get the boat."

"I'd forgotten, sir," said Frank.

Lord Hastings scribbled rapidly on a piece of paper, which he passed to Jack.

"This will fix you up," he said. "Now remember, 10 o'clock sharp."

The boys nodded their understanding of this order, saluted and left. Getting their things together, they hurried to the river, where Lord Hastings kept his motorboat; and an hour and a half later they were proceeding slowly down the river.

"Guess none of the enemy will ever get in here," declared Frank, after a careful survey of the river.

"Guess not," replied Jack. "Look at the boats. You wouldn't think we were at war."

"Not if it wasn't for the warships," agreed Frank. "And there are enough of them to make it hot for any hostile fleet. But it's a wonder to me some of these German submarines haven't taken a little trip up the Thames."

"Mines," replied Jack briefly.

"True," said Frank, "but you will remember we took a pretty long jaunt up the Dardanelles, and passed through the Kiel canal."

"And when you stop to think of it, we're pretty lucky to be here right now," returned Jack dryly.

"Well, so we are, if that's the way you look at it. However, I wouldn't mind having another such chance."

"You'll probably get it."

Conversation lagged as the boys took in the scenes about them; and there was little more talk during the trip. They stopped more than once, and, loitering along, it was dark when they neared their destination.

As they would have drawn up to the wharf there was a sudden flash of light—gone in a moment—followed by a dark body that swished by them like a flash.

Frank uttered an exclamation of astonishment.

"See that?" he demanded.

"Yes. What could it have been?"

"You've got me, but it's heading toward the open sea. Great Scott! Maybe it's an enemy."

"An enemy?"

"Yes; you know how anxious the Germans are over this submarine business. Maybe this fellow has been spying about. May be going to report to a German submarine out there some place."

"Think we had better follow and have a look?" asked Jack.

"Believe it would be a good idea. Let's go."

Without another word, Jack brought the boat about and headed after the one that had so recently dashed by them. In the darkness ahead there was nothing to be seen.

"Like looking for a needle in a haystack," Jack called to Frank.

"That fellow can't be up to any good," declared Frank. "He showed no light and was going in a terrible hurry. There's something up."

"Does seem that way," agreed Jack.

"Say! Is this as fast as this thing can go?" demanded Frank. "We won't ever get any place this way. Let her out a bit."

Jack did so and the little boat seemed literally to fly over the dark water. This terrific speed Jack kept up for some time and then slowed down.

"We'll bump into something at this rate," he said; "and that would settle the whole business. We must be cautious."

"Cautious!" repeated Frank. "We won't find that German being cautious."

"If we weren't cautious, it wouldn't do us any good if we did find him," argued Jack. "First thing you know we would be at the bottom."

Frank considered this point a moment.

"Guess you're right," he said at last.

"Swish!" went something at this moment, and, turning quickly, Frank saw a dark shape speeding away up the river.

"Hey! There went one the other way," he cried to Jack.

"That so?" replied Jack anxiously. "There is something up here, and I'm going to find out what it is."

He slowed down even more, and, striking a match, lighted the searchlight, which, until this moment, he had not deemed advisable.

As the light flashed over the water, the lad made out another small motorboat dead ahead, upon which signs of life became apparent. Jack saw figures gesticulating violently; then the boat headed directly for the one occupied by the two boys.

"Guns, Frank!" said Jack quietly. "They are coming at us."

"Leave it to me," replied Frank. "You run the boat. I'll do the rest."

"Don't shoot unless you have to," warned Jack.

Frank made no reply.

Jack kept the light full upon the approaching boat. He could see several oilskin-clad figures and that was all; and then came a hail from the oncoming boat.

"What do you want here?"

The query was in English. Jack answered the hail.

"What are you doing here yourself?" he demanded. "We are British officers. I command you to surrender."

"More likely German officers," was the response. "Heave to now. I'm coming aboard you."

"If you do you'll get a warm welcome," replied Jack.

He stopped the boat and drew his own revolvers.

"Stand back!" he cried, as the other boat came closer.

In the glint of the searchlight the men aboard the other boat made out the boys' uniforms. The boat slowed down and the men talked among themselves.

"They wear British uniforms," said one in a low voice.

"That's no sign they are English," said another.

"Tell 'em to give the countersign," said a third.

Another hail came from the boat.

"Pass the countersign," it said.

"I don't know any countersign," replied Jack, and would have said more, had not a voice from the other boat interrupted him.

"I thought not; hands up now or you are dead men. Quick!"

Jack made his decision in a moment. Much as he would have liked to fight it out, he determined upon a wiser course.

"Hands up, Frank," he said quietly. "They've got the drop on us."

He raised his hands in the air.

Not so Frank.

"They won't get me without a fight," declared the lad angrily, and, raising his voice, he cried:

"Come and get me, if you want me."

At the same moment he raised his revolver and fired.

"Here," cried Jack angrily, "don't be a fool. Give me that gun."

He seized Frank's wrist and wrenched the revolver from his grasp.

The latter turned on his chum angrily.

"What do you mean by that?" he demanded. "Have you turned coward, that you surrender to a couple of Germans without a fight?"

"I haven't turned crazy," replied Jack quietly. "They are too many for us; that's all."

The other boat came alongside now and an officer stepped aboard the boys' craft.

"Your weapons," he said in perfect English.

"Then please step aboard my boat. You shall be taken to Gravesend at once."

"Gravesend!" echoed Jack. "You couldn't take us to a better place. But if you are German, why should you take us there?"

"German," repeated the man. "You know we are English. You are the German spies."

"No such thing," declared Frank, taking a hand in things. "We are British officers and we thought you were German spies. That's why I fired at you. We thought you were here to learn the secret of the vanishing submarines."

"Frank!" cried Jack in warning, but it was too late.

"The vanishing submarines, eh?" repeated the stranger. "So you have given yourselves away. Who but a German spy would be here seeking word of the vanishing submarines?"

"But I tell you——" began Jack.

"Silence," thundered the officer. "You have betrayed yourselves, and that is enough. I give you my word you shall be shot in the morning."

"Oh, I guess not," replied Frank with a laugh. "I guess Lord Hastings will be able to get us out of this mess."

"Lord Hastings?"

"Why, yes, we happen to serve under him; that's all."

"Tell it to the marines," replied the man with sarcasm. "I am not asking you to admit anything, for I know enough now."

"Oh, all right," said Frank.

"Climb into my boat," ordered their captor.

The lads complied.

"Say," said Frank, "this is Lord Hastings' motorboat. He told us not to lose it. Tie it on behind and pull it along, will you?"

"We'll pull it along all right," replied their captor. "Now the best thing you fellows can do is to keep quiet."

The lads obeyed this gruff command, for they had nothing particular to talk about.

Half an hour later the motorboat docked at Gravesend and the boys were ordered to climb out, which they did, under the noses of their captors' weapons.

"Where to now?" asked Frank.

"Where I tell you," was the reply.

Jack was struck by a sudden thought.

"Will you tell me what time it is, sir?" he asked the leader of the party which surrounded them.

"As you ask in such a polite way, I shall do so," was the reply. "I wouldn't tell this other fellow anything. He's too smart." He produced his watch, and after a glance at it, said: "Five minutes to ten."

"By George!" exclaimed Jack. "And we were to meet Lord Hastings at the Lion Inn at 10 o'clock."

"I can promise you'll be at the Lion Inn at 10 o'clock," replied the leader of the capturing party, "but whether you will find Lord Hastings there I can't say."

"You mean you are taking us there?" asked Jack.

"Exactly."

"That's what I call luck," broke in Frank. "We'll be all right in a few moments now, Jack."

"You'll be all right till in the morning, I can guarantee that," growled their captor.

At the door of the inn he motioned them to enter ahead of him. They did so and the first person on whom their eyes rested was Lord Hastings.

"Well, I see you are on time——" the latter began, and then broke off as he saw the armed men behind them.

"Yes, sir, we are on time," replied Frank with a smile, "and we have brought company to see you, sir!"

CHAPTER III.

A LESSON.

Lord Hastings was on his feet by this time and advanced toward the two lads and their captors.

"What's the meaning of this?" he demanded of the man who appeared to be the leader.

"We caught these fellows scooting down the Thames in a high-power motorboat, sir," was the reply. "They were unable to give a satisfactory account of themselves and one of them took a shot at us. So we brought them here."

"Do you know who they are?" asked Lord Hastings, smiling a bit to himself.

"No, sir; but I would take them for a couple of German spies, sir."

"H-m-m," muttered Lord Hastings. He stroked his chin a moment and then asked: "And what do you intend to do with them?"

"Turn them over to Colonel Masterson, sir, who will return about midnight. He is stopping here, sir."

Lord Hastings seemed to consider the matter a few moments, and then, with a gesture, he turned on his heel, remarking:

"Well, I can't see that it is any of my business."

"Very good, sir," said the boys' captor.

Frank and Jack had remained quiet up to this time, but now the former took a step after his commander, exclaiming:

"Aren't you going to get us out of this, sir? You can explain that we have done no wrong."

Lord Hastings turned toward him.

"I have this officer's word," he said, indicating the boys' captor, "that you were captured under suspicious circumstances. I thought I knew you—both of you—but it may be that I have been mistaken. Stranger things have happened than for a man to sell out to the enemy. I cannot interfere with the officer in the performance of his duty."

"But, sir——" began Jack.

Now the officer interrupted.

"You know them?" he asked of Lord Hastings.

"I thought I did," was the reply. "It would seem that I have been mistaken."

"I should say it does," said the officer. "Certainly they were making their way down the river for no good purpose."

"I am afraid I must agree with you. However, I shall not interfere. You may do as you think best with them."

"Very good, sir." The officer motioned the boys to precede him to the stairs at the far end of the room. "Up with you," he commanded.

Frank hung back.

"Prod him up a bit there, men," instructed the officer.

A second man advanced and pushed his revolver against Frank's ribs.

"Move along," he commanded gruffly.

"Now look here——" began the lad, but Jack interrupted him.

"Come, Frank, don't be a fool," he said.

He led the way up the stairs, and Frank, still grumbling, followed. At the top of the steps the boys were marched into a small room. The door closed behind them and a key turned in the lock.

"Now," said Frank, turning to his friend, "what is the meaning of all this?"

"You know just as much about it as I do," was the reply.

"But a word from Lord Hastings would have settled all this."

"But he didn't give it, did he?"

"No, he didn't; and that's what seems so strange. It looks to me as though we are in for a peck of trouble."

"Say! you heard what Lord Hastings said about 'selling out.' Do you think he believes us guilty of such a thing?"

"It's hard to tell what a man believes in times like these. Men have been stood up against a wall and shot on less evidence. You remember taking a shot at the other boat, don't you?"

"Yes, but——"

"'Buts' won't help us any, I'm afraid. I can't account for Lord Hastings' actions, but you may be sure he has good reasons for whatever he does. It may even be true that he suspects us."

"By George! I don't believe that," exclaimed Frank.

"It doesn't seem possible; but still you can't tell."

"But what are we going to do?"

"Do? There is nothing we can do. We'll have to stay here until they decide what to do with us. There is nothing else to do."

The boys kept up their conversation for some time, and the more they talked the more they became convinced that their plight was more serious than they had at first supposed. It seemed very plain to them now that Lord Hastings must believe in their guilt and that he would not raise a finger in their behalf.

It was after midnight and the boys were still talking when the key again turned in the lock of the heavy door. It swung inward and their captor entered.

"Down stairs," he said briefly, motioning them to march down ahead of him.

The lads obeyed this order.

There was no one in the room below; and the lads sat down before the fireplace to await whatever might transpire.

"There will be no use trying to escape," said their captor. "The place is surrounded. You would be shot down like dogs. Now just be as comfortable as you can. I have business elsewhere."

He wheeled about quickly and disappeared through the door and the lads heard him lock it after him.

"Well, why are we allowed to sit here in solitary glory?" asked Frank.

"Ask me something easy," returned Jack. "We're here; that's all I know about it. However, I don't imagine we shall be here alone very long."

And he was right, although the first corner could not possibly have been in his mind, nor the nature of his coming.

Jack's attention was attracted toward the window by a slight squeaky sound. The lad glanced toward it, but no second sound followed immediately.

"Sounded like some one at the window," he said to Frank.

"I didn't hear anything," said the latter.

A moment later the noise came again. Jack sat up straight in his chair.

"Hear that?" he asked.

Frank nodded affirmatively.

"Some one there, all right," he agreed.

He made as though to rise, but Jack stayed him.

"Wait and see what happens," he said softly.

Both leaned back in their chairs and seemed to pay no further heed to the window. But without looking each became aware that the window was being raised softly, and clear across the room they could hear the breathing of a man. A foot sounded on the floor and at that moment both boys sprang to their feet and faced the intruder.

Before either could speak, the newcomer laid a finger to his lips in a sign for silence and came toward them.

"Quick!" he whispered, when he was close to them. "Tell me what you have learned. This may be your only chance!"

Frank and Jack stepped back in astonishment.

"Tell you what?" demanded the latter.

"What you have learned," repeated the man. "About the vanishing submarines. What has happened to them?"

Noticing the apparently puzzled looks on the faces of the two boys, the man smiled slightly and thrust a hand into his inside vest pocket.

"I see," he whispered. "You want to be sure it is all right. Here. Look!" he exhibited a small card. "My number. Thirty-two. See it?"

Jack's quick mind took in the situation on the instant.

"But you are no German," he protested.

"No, I'm English. Name of Davis. But I am in the game for what it's worth, the same as you are."

"I see," said Frank. "And you have been sent after our information?"

"Yes; and I shall have to hurry. We may be interrupted at any moment."

"We haven't had time to jot down anything," said Jack, "but we'll tell you what we have learned."

He whispered for some moments and Davis nodded understandingly. At last the boy ceased his whispering.

"And that's all you know?" asked Davis.

"Absolutely all," replied Jack, and added to himself, "and a whole lot more than I know, for that matter."

"Then," said Davis, "you believe that if we can get to the mouth of the Thames we can learn the whole secret?"

"That is my opinion," said Jack.

"Good; then I'll pass the word along. Good-bye."

Davis moved toward the window and a moment later disappeared on the outside.

"Now," said Frank to Jack, "just what did you tell that fellow? I couldn't hear all that whispering."

"Well," replied Jack, "I told him we had learned very little; but that the secret of the whole affair was at the mouth of the Thames; that that was where we were heading for when we were captured."

"And did you give him some kind of a hint as to the nature of the mystery?"

Jack smiled.

"Well, yes," he said. "I told him he would find some queer explosives there and a large number of swift torpedo boat destroyers, equipped with submarine nets. I told him that these made nightly raids into the Channel and the North Sea and thus disposed of the German submarines."

"And he believed it?"

"He seemed to. But that was the best I could do on short notice and knowing no more than I do of the matter."

"Well, it wasn't so bad," grinned Frank.

"I flatter myself that it could have been worse," returned Jack modestly.

They fell into a long silence, which was suddenly broken by Frank, who exclaimed anxiously:

"Say! Do you suppose that could have been a trap?"

"Trap?" repeated Jack. "What do you mean?"

"I mean, do you think Lord Hastings or some of the other British officers sent that man here simply to get evidence against us?"

"By Jove!" exclaimed Jack. "I never thought of that. Whew! Maybe I have gotten us into worse trouble than ever."

"If it was a trap, I guess you have," returned Frank glumly. "Yes, it was a good job you did, I don't think."

"Wait a minute, though," said Jack. "If it were a trap, it would be plainly evident we didn't know what we were talking about. That should be enough to let us out."

"Unless they believe we smelled a mouse and acted accordingly," returned Frank.

"Oh, well," said Jack, "there is no use worrying about it. We'll have to take what comes and that's all there is about it. Now, I'm going to rest a bit. When they come in, wake me up."

He leaned back in his chair and closed his eyes; and in the meantime Frank continued to turn events over in his mind.

Half an hour later Lord Hastings, the man who had led the party that captured the boys, a figure attired in the uniform of a colonel of infantry, and several others entered the room. The uniformed man Frank immediately took to be Colonel Masterson, and he was right. Frank nudged Jack and the latter opened his eyes. Then both boys got to their feet.

"So these are the German spies, eh?" said Colonel Masterson.

"That's not true," declared Frank hotly. "We are no more spies than you are."

"So?" said the colonel insinuatingly. "Then how does it happen you hold such friendly conversation with another man who is under suspicion?"

Frank's heart sank. So it had been a trap, after all.

"I can explain that, sir," said the boy, turning to Lord Hastings.

"I have no doubt of that," was the reply. "The question is, can you explain it satisfactorily?"

"Yes, sir, we can," interrupted Jack.

Here Colonel Masterson took a hand again. He spoke to Lord Hastings.

"What shall we do with them?" he asked.

"That, colonel, is for you to decide," was Lord Hastings' reply.

"Do you think it necessary to call a court martial?" continued the colonel.

"In view of the evidence we have, I should say not," returned Lord Hastings.

"And still," said Colonel Masterson, half to himself, "it seems to me that every man should be given a chance."

In the minds of the two boys now there was not the slightest doubt that they were in as perilous a situation as they had ever faced.

"Lord Hastings," said Jack quietly, "I assure you you are all mistaken. However, we shall protest our innocence no longer, for I see it would be useless."

And then the two lads were treated to one of the surprises of their lives. Lord Hastings' stern expression gave way to a smile, and he strode quickly toward them and extended a hand to each.

"Surely," he said, "you didn't think I doubted you."

The lads were too stunned to say a word.

"I just wanted to teach you a little lesson," continued Lord Hastings. "In the future, perhaps you will neither fall short nor go beyond your orders. I ordered you to Gravesend. You should not have gone beyond."

"But Davis, sir?" exclaimed Frank.

"As long as you were here, apparently prisoners," was the reply, "I simply used you to advantage. Davis is a German spy."

CHAPTER IV.

STRANGE WARFARE.

It was the following night.

Clad in heavy oilskins, Frank and Jack stood in the bow of the large, high-powered motorboat as it sped down the Thames in the darkness. Not a light was visible anywhere and it was impossible to see a yard ahead. But in spite of this, the boat fairly flew over the water; for the strong hand of Lord Hastings was on the wheel and there was not a spot in the river with which he was not familiar.

"Whew!" said Jack, as he turned about to shield his face from the icy spray. "This is what I call taking a long chance, if you ask me."

"I should say so," replied Frank, raising his voice to a shout to make himself heard above the sound of the whistling wind. "Wonder how long we are going to keep this up?"

"Don't know," responded Jack. "But I don't feel very comfortable. This is too fast for me."

"Particularly when you can't see where you are going," Frank agreed.

Both became silent and peered into the intense darkness ahead.

For possibly half an hour the motorboat continued its terrific speed; and then it slowed down abruptly. The two boys heard Lord Hastings call them. They felt their way to where he stood by the wheel, for it was impossible to see.

"Here," said their commander, "take this searchlight and flash it ahead. See if you can pick up anything."

He passed a small but powerful searchlight to Jack, who again moved to the bow.

Jack pressed the little button and a tiny but brilliant light flashed over the water before the boat. There was nothing in sight, so far as the boy could see.

"Nothing ahead, sir," he reported to Lord Hastings.

"Guess we had better remain about here, anyhow," muttered Lord Hastings, half to himself.

Although the lads had no idea of the nature of their present mission, they had asked no questions of their commander. They knew he would tell them whatever he deemed necessary when the time was ripe; and until that time they were satisfied to await whatever might transpire.

But one thing the boys had noticed which had given them much food for thought. In the prow was mounted a small but heavy gun, and a second one of the same size loomed up formidably astern. Plainly they were there for a purpose, and Frank and Jack both realized that there was serious work ahead of them.

Lord Hastings himself had examined both guns carefully and announced that they were in first-class condition.

"All ready for use," he had said.

And now, although neither lad knew it, the time was fast approaching when they were to be greatly needed.

Several times in the course of the next hour Lord Hastings ordered Jack to see what he could pick up ahead; but each time the result had been the same. There was nothing to disturb the calm peacefulness of the night.

And then they were spared the need of another look, for there suddenly loomed up less than a hundred yards ahead a dull-glowing white light.

"To the forward gun, Mr. Templeton," ordered Lord Hastings, thus, for the first time on this mission, falling into old aboard-ship terms.

Jack sprang forward.

"Man the gun astern."

Frank obeyed this command with alacrity.

Then the two lads awaited developments.

Apparently the craft ahead had not discovered the presence of the motorboat containing Lord Hastings, Jack, Frank, and a crew of four men; neither did the distance between the two boats seem to diminish. The two were not approaching each other.

"Twenty-five knots," came Lord Hastings' command, and the little craft seemed to leap ahead.

The light ahead drew closer.

"Train your gun on her, Mr. Templeton," ordered Lord Hastings, "and if I give the command, fire to sink her."

This command was needless, for Jack had already gauged the range and trained the gun. Nevertheless he replied:

"Yes, sir."

The pursuers now had approached within fifty yards of their quarry, and still not a sound save an occasional order from Lord Hastings had broken the stillness of the night. There had been nothing to indicate that the other boat was even occupied, save the sudden appearance of the light aboard.

But now, as the pursuers crept even closer, there came a sudden startled exclamation from ahead; and at the same moment the light disappeared.

"Fire!" cried Lord Hastings.

"Boom!"

Jack had fired the gun.

There was another startled exclamation from ahead.

"Did you hit her?" asked Lord Hastings.

"Think so, sir," replied Jack. "Don't see how I could have missed at that distance."

"We'll cruise about a bit and see," said Lord Hastings.

He gave the command and the motorboat slowed down.

For half an hour the little craft circled about, but there was no trace of the other boat. All aboard flashed searchlights about the water, and the larger light in the bow was turned on, casting a bright ray over the water.

"They've either gone away or to the bottom, sir," said Frank.

"And I guess it's away," said Lord Hastings. "Jack must have missed."

"Don't see how I could, sir," declared the lad.

"Better let me try with a revolver next time," put in Frank. "I know I could have landed one of them."

"Well, they have gone. But we'll get them if we have to follow them for a month."

"Who, sir?" asked Frank, who could restrain his curiosity no longer.

"Why, your fellow conspirators, Davis and Baron Blosberg."

"Baron who?" asked Frank.

"Blosberg. He is the man we are after. We have evidence to prove that he is at the head of a body of spies that have been divulging our plans to the enemy. Davis is merely one of his instruments."

"I don't know anything about the baron," interrupted Jack, "but if he is anything like Davis, I haven't any use for him on general principles."

"He's just a bit worse, if that is possible," declared Lord Hastings.

"Then we shall have to get him," declared Frank.

"Right," agreed Jack. "A man like that is too dangerous to be running around loose."

"We may as well proceed then," Lord Hastings decided. "The chances are we shall find them at the mouth of the river. However, we will hardly pick them up before daylight."

And Lord Hastings was right.

Day dawned cool and grey, and in spite of their heavy oilskins, Frank and Jack were chilled to the bone from their long stay in the cold. Several times Lord Hastings had asked them if they wished to go below and warm up a bit, but each was too interested to leave his post for a moment.

"Can't tell what minute we may run across them, sir," Jack had said, "and I want to get even for the miss I made a while ago."

A slight fog rose over the water. Lord Hastings gave an exclamation of impatience.

"Even the elements conspire against us," he said aggrievedly.

"It's not much of a fog, sir," said Jack. "It may lift at any minute."

But it didn't lift, and at noon was as dense as before.

But the very fact of the fog finally brought the pursuers upon their quarry.

A small boat appeared suddenly perhaps a hundred yards ahead, barely visible in the gloom.

"Looks like them, sir," declared Jack.

"What makes you think so?" demanded Lord Hastings, at the same time throwing over the wheel.

"I don't know, sir," replied Jack. "I don't really mean it looks like them. I just think it is them. It's what Frank would call a—a—a——"

"Hunch." Frank supplied the word.

"That's it," agreed Jack. "A hunch, sir."

"We'll see," said Lord Hastings grimly.

At this moment the occupants of the craft ahead realized that they were pursued. The boat bounded ahead with a sudden burst of speed.

"It must be they," declared Lord Hastings. "If they were not here for some ulterior purpose they wouldn't run."

He signalled full speed ahead and the motorboat sprang forward.

"Shall I have a shot at them?" shouted Jack.

"Not yet," replied Lord Hastings. "It may not be the boat we are after."

The race continued.

Suddenly the foremost boat swerved sharply to the left, then dashed straight ahead again.

"They are heading for the shore, sir!" shouted Jack.

The pursuing boat also swerved sharply, one side dipping to the water's edge and all but throwing Jack overboard.

"So they are," replied Lord Hastings, "Gun ready, Mr. Templeton?"

"All ready, sir."

"Good. Try and do better this time. Fire!"

"Boom!" went the little gun, and all strained eagerly forward to watch the result of the shot.

A volume of water shot up a few yards behind the pursued.

"Missed again," said Frank sorrowfully.

"Again," commanded Lord Hastings. "Fire!"

And the second shot also went wide, for even as Jack fired the boat ahead again swerved suddenly. Now the pursued began to steer first to one side and then to the other, momentarily approaching closer to shore, however.

Twice more Jack fired in response to Lord Hastings' command, but the result was always the same. As long as the pursued continued to zig-zag there was little hope of a successful shot.

But in the meantime the pursuers were gaining. A bullet from ahead whistled over Frank's head.

The lad grew angry and drew his own revolver. Taking careful aim, he fired. So far as he could see there was no result.

"Where's that infallible aim of yours?" demanded Jack.

Frank made no reply but fired again. This time his effort was rewarded.

A figure straightened up in the boat ahead, waved his arms above his head, and with a cry toppled into the water. The boat did not slow down. The others plainly did not intend to take the time to attempt a rescue.

"Shall we pick him up, sir?" asked Frank.

Lord Hastings shook his head.

"We have more serious business in hand," he replied. "He will have to take his chances."

Still the pursuers gained; but it became apparent now that they could not hope to overtake their quarry before he reached shore.

"Ready to take a shot as they jump out of the boat," was Lord Hastings' command.

All drew their revolvers and stood ready.

Now, there was little doubt in the minds of all that they could pick off the fugitives as they leaped ashore, and they probably would have done so but for an unforeseen occurrence.

The pursuers had lost a little time in maneuvering to get in an effective shot, and the pursued now were more than a hundred yards ahead.

As the first boat was a scant fifty yards from shore, a third craft hove in sight, headed down the river. It was going in such a manner as to pass directly between pursuer and pursued as the latter landed.

In vain Lord Hastings signalled the third boat to stop. It came on, paying no heed; and what Lord Hastings feared came to pass. Just as the first boat grounded and its occupants leaped ashore, the third craft passed between the first and the pursuers. Although all held revolvers ready, there was no chance to fire; and when the pursuers reached shore their quarry were some distance away.

"After them!" cried Jack.

CHAPTER V.

THE END OF BLOSBERG.

Lord Hastings and Frank needed no urging. With a cry to the other occupants of the boat to remain there until they returned, Lord Hastings leaped lightly ashore and dashed in pursuit of the fugitives. Jack and Frank were close at his heels.

All had drawn their revolvers and a weapon swung in the right hand of each as he sped over the ground.

Ahead the fugitives had redoubled their efforts. A quick backward glance had showed them they were pursued and now they sped over the ground as fast as their legs would carry them.

Frank gradually forged ahead of the others. At school the lad had always been known as something of a sprinter and his training stood him in good stead now.

"Wait for us," panted Lord Hastings, but Frank paid no heed and continued to lengthen the distance between himself and his friends.

The fugitives had now reached the first street off the waterfront and were dashing along it madly, still more than a hundred yards ahead of Frank, their nearest pursuer. Strangely enough, there was not another soul in sight at this minute, for they were still at the extreme edge of the city.

But at this moment a man suddenly came out of a building ahead and stood looking at the running men curiously. Frank raised his voice.

"Stop 'em!" he shouted.

The man stepped directly in front of the fugitives and threw up a hand, signifying for them to halt. But the fugitives had no time to waste on him. Frank saw Davis, who was slightly in advance of Blosberg, extend his arm before him; and a moment later the man who would have stayed the fugitives' progress went sprawling in the street. In the language of the football field, Davis had "stiff-armed" him.

Neither Davis nor his companion had slowed up for this maneuver, so the pursuers had gained nothing because of the stranger's attempt to aid them.

Davis and Blosberg now came to a cross street and turned the corner without slackening their speed. Frank, still gaining steadily, darted around it a few seconds later, now less than seventy-five yards from his quarry. Lord Hastings and Jack, running about evenly, were still fifty yards behind Frank.

The fugitives doubled around the next corner without diminishing their speed and Frank did likewise. The next corner saw the same maneuver enacted, and this time Frank brought up against trouble as he followed unwarily.

As the lad turned the corner something struck him in the face and he went tumbling to the ground in a heap. He felt as though he had collided with a wall. He was just picking himself up when Jack and Lord Hastings darted around the corner and almost stumbled over him.

Jack would have stopped, but Frank shouted:

"After them! Never mind me."

Jack and Lord Hastings dashed on, and Frank pulled himself up and took account of his injury. A stream of blood flowed from a cut just over his left eye, but Frank knew that he was not badly hurt.

"One of them bumped me with his fist," the lad told himself. "I wonder which? Guess it must have been Davis. I don't believe a German could do as much damage with his hand."

Quickly he staunched the flow of blood and then darted after Jack and Lord Hastings, who at that moment were disappearing around another corner.

In spite of the cut on his face, Frank felt greatly refreshed by his enforced but brief rest, and he took after the others with renewed energy.

"They must be getting pretty tired," he told himself as he dashed along. "If Jack and Lord Hastings can just keep them in sight until I overtake them, I'll promise not to be fooled again."

Two minutes later he was again on even terms with Jack and Lord Hastings, and a moment later once more took the lead. A minute later he again found himself less than fifty yards behind the fugitives, who were now plodding along more slowly and plainly out of wind.

"A little sprint here, I guess," Frank muttered to himself, and suited the action to the word.

But the fugitives were able to round another corner before the lad could come up with them. Remembering his past experience, Frank turned the corner more warily and then he came to a dead stop, a cry of dismay on his lips.

There was no one in sight.

"Now what in the name of all that's wonderful can have happened to them?" he asked himself.

He looked around quickly. The fugitives were not on the street. Frank gazed at the house before which he stood. It was a two-story brick building and stood right upon the street. There was no yard. A flight of eight stone steps led to a small vestibule.

"Guess they must have gone up there," the lad muttered.

He moved up the steps just as Lord Hastings and Jack hove in sight around the corner. They pulled up at Frank's side.

"Where did they go?" demanded Lord Hastings.

"I don't know," replied Frank, "unless they went in this house."

"We'll have a look," said Lord Hastings briefly, and mounted the steps.

Frank and Jack followed him.

Lord Hastings turned the knob and the door opened easily.

"Look out, sir," warned Frank. "They're liable to take a shot at you from some place."

Lord Hastings did not reply, but issued orders rapidly.

"Frank, you take the rear door. If it's locked the chances are they are in the house. Jack, hunt the door to the basement and stand guard there, also keeping an eye on this door if possible. I'll try and round them up."

The two lads nodded their understanding of these orders. Jack found a door leading to the basement, in the hall, fortunately still in view of the front door. Frank dashed to the rear of the house and found the back door still locked.

"They must be in here, then," declared Lord Hastings.

He examined his revolver carefully and then, holding it ready for instant use, entered the front room. There was no one there.

In vain Lord Hastings explored all the downstairs rooms. There was no one to be found. He came again into the hall.

"Must be upstairs," he said to Jack as he passed him.

He mounted the stairs rapidly, though cautiously. In the first room he entered he found nothing. The door of the second room was shut. Lord Hastings laid a hand on the knob and turned it. The door opened easily and Lord Hastings stepped over the threshold.

And even as he would have moved into the room a hand, gripping the barrel of a revolver, was raised in the air and descended violently in the direction of Lord Hastings' head. Fortunately the latter caught the glint of steel and whirled in time to dodge the blow and grasp the arm that delivered it. At the same time he shouted:

"Frank! Jack! Upstairs!"

Then he gave his entire attention to his foes, of whom he now found, there were two. Lord Hastings recognized the man whose arm he grasped as Davis. Blosberg, with levelled revolver, was circling about the struggling figures, seeking an opportunity to shoot Lord Hastings without wounding Davis.

With a mighty effort Lord Hastings lifted Davis clear of his feet and, exerting tremendous strength, swung him around. There was a sound of a thud, and Davis' figure dropped limply to the floor. His head had come in contact with the solid wall.

At the same moment Blosberg fired and Lord Hastings felt a stinging sensation in his left shoulder.

He staggered back.

Blosberg took advantage of this and darted out the door just as Frank appeared at the top of the steps. Both raised their revolvers at the same moment, but Blosberg was the first to fire.

Frank's gun seemed to explode in his hand. It leaped in the air like a live thing and the lad felt a strange sensation in his hand. He wiggled his fingers, but now he was unable to tell whether he had a right hand or not. There was no feeling there. Blosberg's bullet had struck the lad's revolver and the shock had numbed the lad's hand.

Before Frank could recover, Blosberg had darted down the hall and turned into a narrow passageway at the end of it, disappearing just in time to escape a bullet from Jack's revolver, the lad appearing on the second floor at that moment.

He dashed after Blosberg.

Turning off the main hall into the narrow passage at the end, Jack brought up sharply against an object in the semi-darkness; but he found no Blosberg. Quickly he took a match from his pocket and struck it. There was no sign of Blosberg, and Jack made out that the object that had interrupted his progress was a ladder leading upward toward the roof.

"He's up on the roof," cried Jack. "Come on."

Without taking thought of what danger might be in store for him above, he mounted the ladder rapidly.

When Blosberg reached the roof he had replaced the trapdoor, but he wasted no time, and began looking for a means of descent. He still held a gun in his hand and whirled sharply as the trapdoor suddenly flew open. He saw Jack at the same moment Jack saw him, and both fired.

But the aim of each was poor and Jack followed his shot by leaping to the roof. Then he dropped down suddenly as Blosberg fired again, and, still unharmed, drew himself quickly behind a chimney nearby. Blosberg took refuge behind a second chimney.

Now Lord Hastings' head appeared and drew back suddenly as Blosberg took a quick shot at him.

"All right, sir, come on!" called Jack. "I'll get him if he tries to pot you again."

Lord Hastings sprang through the opening and a moment later Frank also appeared on the roof. Blosberg made no effort to fire again, apparently realizing the hopelessness of his case.

Frank and Lord Hastings now had taken their places with Jack behind the chimney.

"Well, we can't fool around here all day," said Jack. "We'll circle about and one of us can get him."

Lord Hastings, wounded, was left behind the chimney, while Frank, who had produced another revolver, leaped out suddenly to the left, Jack at the same time springing to the right. Then they moved forward.

"Hold on," came Blosberg's voice at this moment. "I surrender."

The three friends breathed easier.

"Drop your gun and come out—and have your hands in the air," ordered Jack, still holding his revolver ready.

A moment later Blosberg appeared, unarmed.

Jack lowered his own weapon, and as he did so Blosberg, with a sudden cry, dashed forward and leaped off the roof into space.

For a brief instant Jack was stunned; then he dashed to the edge of the roof and peered over. He saw Blosberg's twisting, tumbling body crash head-first upon the hard walk, and then lay still.

CHAPTER VI.

WITH THE MOTORBOAT FLEET.

Frank and Lord Hastings also came quickly forward and peered over the edge of the roof.

Jack wiped beads of perspiration from his face; then turned and lifted his hat.

"That," he said quietly, "took nerve; for he must have known he would be killed."

"But he preferred it to falling into the hands of an enemy," said Frank. "He was a brave man."

"Come," said Lord Hastings; "we shall go down and carry him into the house. Then we shall notify the civil authorities and they can take charge of his body."

They made their way down stairs and tenderly carried the body of the Baron into the house, where they stretched out his mangled form as well as possible and covered it with a sheet. Lord Hastings went to the telephone in the hall and notified the authorities.

"Well," he said, "we may as well go now."

"How about your wound, sir?" asked Jack. "I saw blood on your coat a moment ago."

"True; I had forgotten," replied Lord Hastings.

He stripped off his coat and Jack examined the wound.

"Just a scratch," he said cheerfully. "I'll fix it up in a jiffy, sir."

He did a neat job and Lord Hastings again donned his coat and turned to go.

"Wait a minute, sir; you are forgetting something," exclaimed Frank.

"What's that?" asked Lord Hastings in surprise.

"Davis, sir."

"By Jove! I had forgotten all about that scoundrel," said Lord Hastings.

He led the way to the room where he had so recently placed Davis hors de combat, but there was no Davis there.

Lord Hastings was greatly crestfallen.

"I should not have forgotten him," he said. "He may work more mischief around here."

"The chances are, knowing he has been discovered, he'll make himself extremely scarce," suggested Frank. "He'll probably figure that his usefulness here is at an end."

"Well, that's probably true," admitted Lord Hastings.

"We'll come across him again some place," said Jack. "I wonder if he recognized us as the ones from whom be obtained his information?"

"I wonder, too," said Frank with a laugh. "If not, he probably believes we are in trouble. Guess he will imagine we have been executed as spies by this time."

"To tell the truth, I don't believe he recognized us," said Jack. "We were too far away for that."

"Except for the time he laid me out down the street there," said Frank ruefully. "Then the chances are he didn't take time to look at me. And he was unconscious when we came upstairs here. No, I don't believe he recognized us."

"Well, I hope we shall have the pleasure of introducing ourselves to him more fully at some future date," said Jack.

"And I have a hunch that we shall," declared Frank.

"There is nothing more to be done here," said Lord Hastings at this juncture. "We'll get back to our boat."

Accordingly they took their leave of the house, and half an hour later were again moving down the waters of the Thames.

"Where to now, sir?" asked Frank.

Lord Hastings smiled slightly.

"Can't wait until you find out, eh?" he replied. "Well, I'll tell you. We are about to do a little submarine chasing."

"Submarine chasing?" exclaimed both lads.

"Exactly."

"Good!" ejaculated Frank. "And where is our vessel, sir?"

"If you will look about a little you will see it," replied Lord Hastings.

Frank and Jack let their eyes roam over the broad expanse of the Thames, but they could see nothing but a few small boats of various sorts—nothing bearing the slightest resemblance to a ship of war.

"I don't see anything that looks like it, sir," declared the boy.

"That," said Lord Hastings, "is because you insist on looking too far away. You don't see it for the reason that you are sitting in it right now."

"What, sir?" exclaimed Frank. "Sitting in it now? You mean we are going submarine chasing in this motorboat?"

"Exactly," replied Lord Hastings.

"But, sir——" began Jack.

"You'll find," interrupted Lord Hastings, "that for submarine warfare there is nothing to equal the motorboat—particularly a swift motorboat such as this; and we are now on our way to join the fleet."

"Fleet? Fleet of what?" asked Jack, with some sarcasm. "Fleet of motorboats, perhaps?"

"Precisely," said Lord Hastings with a smile, and added: "You don't seem to think much of the idea."

"No, I don't, sir," was the reply. "I was in hopes that we were to feel a real vessel beneath our feet once more. What good is a motorboat against a submarine, anyway?"

"That's what I would like to know," agreed Frank.

"I'll tell you," replied Lord Hastings. "But first let me ask you something. Do you remember, the other day, of asking me to explain the mystery of the vanishing submarines?"

"Yes, sir," replied both lads.

"Very well. The solution of this mystery is, primarily, motorboats."

"What do you mean, sir?" exclaimed Jack.

"Just what I say. In the main, the possible hundred German submarines that have disappeared recently have been accounted for by high-speed, powerfully armed motorboats. The government has discovered, after much experimenting, that the one craft with an advantage over a submarine is a powerful motorboat; and England now has a fleet of several hundred scouring the seas in the proximity of the British Isles."

"But I can't see where they would do any good," said Jack.

"In the first place," said Lord Hastings, "they are so small that they escape the notice of a submarine until the motorboat is almost upon them; and then it is too late for them to act. Also, the motorboat, being small, is a much more difficult object to hit with a torpedo—it is, in fact, a very poor target. Then again, a motorboat is so much swifter than a submarine that the advantage is all with the motorboat."

"By Jove, sir! the way you explain it I can see the advantages," said Jack eagerly.

"And so can I," agreed Frank.

Lord Hastings smiled.

"You are easily convinced," he replied. "Had some of the admiralty officials been convinced half so easily, this submarine menace might have been effectually stopped long before this."

As the motorboat continued down the Thames, each occupant remained busy with his thoughts. It was Frank who broke the silence.

"What has happened to the torpedoboat destroyers, sir?" he asked. "I understood they were the real submarine foe, with their heavy nets."

"They are still in use," replied Lord Hastings. "You know how they work their nets, I suppose?"

"Why, I think so, sir. The net is carried by two ships, and when a submarine crashes into the net she either tangles her nose or her stern in the net and can be disposed of with ease."

"Yes, but what I want to know," said Jack, "is why she doesn't fire a torpedo through the net and sink the torpedoboat?"

"Because," said Lord Hastings, with a smile, "being beneath the water, she is blind. She doesn't know in which direction to fire it. You forget that the German submarines are not equipped as was the D-16."

"The good old D-16," said Jack. "How I wish we had her again, sir."

"And I," agreed Lord Hastings. "And yet she came near being the death of all of us."

"So she did," said Frank, "but at the same time I wouldn't mind being aboard another such craft."

"Well, just between the three of us," said Lord Hastings, "I may tell you that another such craft now is nearing completion and probably will be at our disposal within a month."

"You don't mean it, sir!" exclaimed Frank happily.

"If he didn't mean it he wouldn't say so," Jack reproved his chum.

"Oh, I know that," replied Frank. "But it seems too good to be true."

"But just where are we bound now, sir?" asked Jack.

"Well," said Lord Hastings, "at first we shall do a little cruising off the Irish coast. In fact, most of the motorboat fleet is in Irish waters. Since the sinking of the Lusitania, most of the work has been done there; and apparently the German government
is still bent upon the destruction of big
passenger ships, neutral or not."

"Well, the sooner we can get busy the better it will suit me," declared Frank.

"I agree with you there," said Jack.

It was a long voyage for the little motorboat, and though Lord Hastings wished to join the others of the fleet at the earliest possible moment, he did not push the little craft, which bore the name of The Hawk.

Therefore, it was late the next day when they came to where the motorboat fleet had its base—Bantry Bay, on the extreme southern coast of Ireland.

As the little motorboat nosed its way into the harbor, several others dashed forward, with guns bared and alert figures standing ready for action. It was not until Lord Hastings had been satisfactorily identified that the warlike atmosphere disappeared.

The two lads looked about curiously. The bay was black with the little craft.

"Great Scott! There are more than two hundred here, if you ask me," declared Frank.

"Looks that way to me, too," agreed Jack.

They mentioned the matter to Lord Hastings.

"Captain Smithers just told me," replied Lord Hastings, "that at this moment there are in the neighborhood of a thousand of these little craft here. However, the bulk of them probably will be sent to other stations before long."

"You mean distributed up and down the coast?" asked Frank.

"Exactly."

"And when are we going to get busy, sir?" asked Jack.

Again Lord Hastings smiled.

"To-night," he said, after a moment's hesitation, "I think I can promise you a little excitement to-night. Captain Smithers has a tip that he intends to follow, and we have been selected for the job."

CHAPTER VII.

AN ENEMY.

The Hawk crept over the still black waters as silently as the night itself. Not a light showed aboard the little craft—not a human voice was heard. Now and then the faint exhaust of the engine could have been heard by a keen ear, but the engine was muffled and whatever sound it might make carried but a few yards at most.

The Hawk, with Lord Hastings, Jack and Frank and the other few members of the crew, was stalking the foe—no particular foe, perhaps—but any enemy that might be foolhardy enough to show itself.

Aboard, each member of the crew, besides his revolvers, was equipped with a small hand flashlight; and the larger searchlight in the bow was ready for instant use—to flash in the eyes of an enemy to blind him and to spoil his aim.

And the two heavy guns—one forward, the other aft—were ready for action.

The men stood at their posts—had stood there now for two hours—ever since The Hawk had crept silently from the friendly shelter of Bantry Bay. The crew had been ordered to silence and the crew of The Hawk, commanded by Lord Hastings, obeyed orders.

So far The Hawk had come upon nothing that had justified its lonesome and silent vigil—not an object of any kind had been encountered, and the hour was now after midnight. Still, keen eyes aboard the little craft peered untiringly ahead and swept the waters in all directions, trying to pierce the darkness of the night.

The night, though dark, was perfectly calm and peaceful, albeit black, overhanging clouds heralded the approach of a storm. But Lord Hastings, than whom there were few better weather prophets, announced that the storm would not break before well along toward morning and held to his quest without trepidation.

Frank and Jack were now becoming somewhat restless, for they had begun to fear that the night's venture would not bear fruit. However, each remembered what Lord Hastings had said regarding a "tip," so they knew that their commander had some object in view. Also, since leaving port, The Hawk had held steadily to her course.

Now and then the commander of The Hawk, by the faint glare of his searchlight, shielded by his hand, consulted a chart and several times muttered low directions to the man at the wheel.

Suddenly there came a subdued command from Lord Hastings, and in response the engines were stopped. Lord Hastings placed a hand to his ear and listened intently.

"Did any of you hear anything?" he asked in a low voice.

No one had.

"Strange," muttered Lord Hastings; "I could have sworn I heard something moving through the water."

He gave the command to go ahead again; but less than five moments later once more brought The Hawk to a pause.

"I am sure I heard something," he said to Frank, who stood near him.

"I thought I did myself, that time," replied the lad. "Sounded like a boat, and not a great distance away."

"We shall have to be careful," said his commander. "I know that there is not another British vessel in these waters to-night. If there is a second craft out here, it must be an enemy."

"Shall we flash our light about?" asked Frank.

"And betray our own presence? Not much. No; we shall just remain here for half an hour and see if we can't pick up the other fellow in the darkness."

Again the silence of death hung over The Hawk.

Then, suddenly, Jack, aft, gave a subdued exclamation.

Lord Hastings hurried to his side.

"What is it?" he demanded.

"Small craft of some kind bearing down on us, sir," he replied quickly. "She'll bump us!"

Lord Hastings took in the situation at a glance. Less than 150 yards away a small object was coming toward The Hawk.

Lord Hastings gave a quick command.

"Full speed ahead!" he cried, and in response to this command, The Hawk leaped forward.

Lord Hastings hurled a second quick command to the man at the wheel, and The Hawk came about in a broad circle; and at the same instant a blinding glare flashed into the faces of all aboard.

A searchlight from the other craft had been turned upon them, lighting The Hawk up like day, while all those aboard could see was the blinding glare, the other boat being shielded by this light.

A shot rang out over the water—the sound of a heavy gun.

Lord Hastings took prompt action, in spite of the fact he could not make out the enemy.

"Turn the searchlight on him!" he shouted.

A second shot rang out and Frank heard the whistle of a heavy missile overhead.

He sprang quickly to the searchlight, and with a single movement, whirled it about. In another moment a second white glare lighted up the sea.

Frank pointed his light squarely at the point from which he could see the other light came. While he was unable to see the other boat, because of its light, he knew that once his own searchlight had found its object, those aboard the other craft would no longer be able to see The Hawk.

Then came the sound of a third shot, but this time the missile was not even heard, and Frank knew that he had been successful. The enemy had lost the range.

"Good!" shouted Lord Hastings. "And just in time, I should say. The next shot would have hit us."

"Yes, sir," said Frank quietly. "He's blinded us, sir, but we have done the same for him. Now what, sir?"

"By Jove! I don't know," replied Lord Hastings. "Here, Jack, stand by this forward gun, and be ready to let her go the first moment you can see the enemy. If we can manage to work out from under his light we may be able to get him. Frank, don't you let that light off him a minute."

"I'll keep it on him, sir," replied the lad.

So there the two boats were, less than a hundred yards apart, but still unable to do one another harm, unless by a chance shot. For, although the occupants aboard each craft could see the light of the other, they couldn't gauge its origin with accuracy.

Several times the enemy fired, but without result.

"Well, we've got to do something," declared Lord Hastings. "Can any of you suggest anything?"

"I believe I have a plan, sir," declared Frank.

"Let's have it quick," said Lord Hastings.

"Well, sir, I should say that if you would stand by the gun, Jack and I can slip over the side in one of the small boats. We'll make a slight detour, to get out of the blinding glare, then row toward the enemy. Without the light in our eyes, we should be able to pick off a couple of the enemy with rifles. Then he'll have to shift his light to hunt new foes. You can be ready and sink him the moment he does so."

"That's not a half bad idea," declared Lord Hastings. "It shall be done. Over with you, lads."

Quickly Frank and Jack got a little boat over the side, procured a rifle apiece, and rowed away.

In spite of the fact that the glare of the enemy's searchlight was squarely upon them, they could not be seen because of the light aboard The Hawk playing upon the eyes of the foe. So, though they rowed rapidly, they knew they were safe enough.

Out of the glare of the searchlight, they shaped their course toward the enemy, whose bulk they could now see looming up in the darkness.

"By Jove! It's another motorboat," Frank whispered.

Jack nodded his head in the darkness, but did not reply.

Less than a hundred feet from the enemy, Frank made out several forms forward.

"This is close enough," he whispered to Jack.

Jack shipped his oars and picked up his rifle. Frank did likewise.

"You get the one on the left; I'll take the one on the extreme right," said Frank. "Then get the one next your first man if you have time before he ducks, and I'll do the same."

"All right," said Jack. "Give the word when you're ready."

"Ready! Aim! Fire!" said Frank quietly.

Two sharp cracks broke the stillness of the night, followed almost instantly by two more.

When the lads lowered their rifles and gazed toward the foe, there was not a man in sight.

"Don't know whether we got them or they just ducked," said Frank. "We'll fire a couple of more shots, enough to make them take their light off The Hawk."

They did so, and a moment later their efforts were rewarded. The searchlight aboard the enemy, moved by an unseen hand, turned and swept the sea carefully.

"Row back!" shouted Frank, and seized his oar.

Jack followed suit. Quickly the little boat was brought about and headed back in the general direction of The Hawk.

And the enemy's boat was now lighted up by the glare of The Hawk alone.

Suddenly the flashlight of the enemy fell squarely upon the two boys.

"We're gone now, unless Lord Hastings sinks them first," said Frank quietly.

"Crack! Crack! Crack! Crack!"

Bullets began to spatter around the two lads. One grazed Frank's ear.

"Guess we had better go overboard," he said, "They'll——"

"Boom!"

The voice of a single big gun spoke once.

"The Hawk!" cried Frank.

"Boom!"

The voice came again.

And then the boys were left again in darkness as the enemy sought out The Hawk with his searchlight.

"Boom!"

It was the third word of the forward gun of The Hawk.

Cries of terror and confusion came from the direction of the foe, followed by hoarse German cries of command.

"Bully for Lord Hastings!" exclaimed Jack. "He has scored a hit."

"Hurrah!" cried Frank, and raised his voice in a series of cheers.

The big gun aboard The Hawk did not speak again, and following The Hawk's searchlight with their eyes, the two lads saw a mass of wreckage floating a short distance away.

"That," said Frank quietly, "is the end of her."

"Right you are," agreed Jack. "Now we'll go back to The Hawk."

Both lads bent to their oars with a will.

CHAPTER VIII.

FRANK IN TROUBLE.

Now perfectly happy, the two boys rowed back to The Hawk as rapidly as possible. They were happy for two reasons—first because they were once more in active service, and second, because they had just emerged successfully from a desperate venture.

A light glowed brightly aboard the little motorboat, now that the enemy had been disposed of; so the two lads had no trouble making their way back. Lord Hastings greeted them with outstretched hands as they went over the side.

"A pretty good job you made of it," he declared.

"Well, we did pick off a couple before you got busy, sir," agreed Frank. "But if you hadn't fired the moment you did they would have potted us sure. They had a couple of shots at us, but fortunately, they didn't have time to get the accurate range."

"I had no idea you were so hard pressed," replied Lord Hastings. "I fired the moment I caught sight of the foe. Even when the searchlight was turned from The Hawk, it was a moment or so before I could make out the enemy. The light had all but blinded me."

"There is no harm done, anyhow," Jack put in. "The enemy is at the bottom of the sea and we are safe again."

"Then we may as well continue a bit," declared Lord Hastings. He turned to give an order, when Frank interrupted him.

"Are you sure we are safe, sir?" he questioned.

"What do you mean?" demanded his commander.

"Why, I was just wondering if by any chance there might be more of the enemy in these waters?"

"To tell the truth, I hadn't thought of that," replied Lord Hastings.

Without another word, he turned on his heel and made his way to the searchlight, which still threw its brilliant rays across the silent waters. Quickly he snapped it off; then returned to the lads.

"We won't be spotted so easily now," he remarked.

"Unless we have been spotted already," said Jack dryly.

And Jack proved to be a better prophet than he really meant to be.

At a signal from Lord Hastings, The Hawk now moved slowly forward again.

"Can you tell us just where we are bound, sir?" asked Jack.

"Well, not exactly," was his commander's reply. "I have information that leads me to believe an enemy, or several enemies, may be prowling about around——"

An interruption came suddenly and from an altogether unexpected source, and with the interruption all aboard became suddenly silent, except Lord Hastings, who sprang quickly to the wheel, and before the astonished helmsman knew what was going on, threw the wheel over hard.

For the interruption which had come so suddenly was the voice of a big gun.

Lord Hastings threw the wheel over with such violence that the motorboat careened desperately and all but capsized. Frank and Jack saved themselves from being thrown overboard by a quick grasp at the rail, to which they clung with all their might.

And then, before Lord Hastings could flash the searchlight across the water, had such been his intention, a blinding glare lighted up The Hawk. The enemy had been too quick for those aboard.

Now another shot rang out and the boys heard a terrible whistling overhead.

"Pretty close," said Jack quietly. "They are liable to get us next time."

An idea suddenly struck Frank, and he dashed aft. There he picked up his rifle and hurried forward again.

"Hold her steady a minute, sir," he called to Lord Hastings.

And the latter, realizing that the lad had some plan, did as requested without asking a question.

Quickly Frank raised his rifle to his shoulder, and pausing just long enough to take careful aim, fired.

Frank's keen mind had detected the one hope of salvation for those aboard The Hawk. The enemy was very close and the lad realized that the next shot must find its mark. There was but one thing to do. The light aboard the enemy must be destroyed; without it The Hawk could escape, for minus the light, which was its eye, the foe could not hope to detect them.

As Frank's finger pressed the trigger he knew that he had not missed; and at the same moment he cried to Lord Hastings:

"Hard-a-port!"

Again The Hawk careened desperately in response to the quick turn of the helm; but it was well that Lord Hastings had acted upon the instant; for even as Frank had fired there was another heavy "boom" and a heavy shell passed the spot where The Hawk had been a moment before.

But with the sound of the shot, the glare of the enemy's searchlight vanished. Frank's aim had been true.

"I shot her eye out, sir," he cried to Lord Hastings.

"I see you did," chuckled his commander. "Now it's time for us to get busy. Mr. Templeton, see if you can pick up the enemy with our light."

Jack sprang to the searchlight eagerly, and under his guiding hand, it threw its brilliant rays over the dark waters. He swept it in a wide half-circle to the right without result; and then swung the glare around to the left; and there, presenting her stern, a little motorboat was moving swiftly away.

"She's running, sir!" exclaimed Frank, who stood forward, still holding his rifle. "Shall I give her a shot?"

"If you like," replied Lord Hastings. "It can do no harm. In the meantime we'll have after her."

He gave the signal, "Full speed ahead," and The Hawk leaped forward.

Again Frank took careful aim at a moving figure upon the deck of the enemy and again his finger pressed the trigger. Not for nothing had he been called a crack shot. The figure, as Frank could see in the glare of The Hawk's searchlight, threw up its arms and pitched into the sea.

And now suddenly misfortune befell The Hawk. The enemy had stolen an idea from Frank, and one of the men aboard, taking aim at the powerful searchlight of The Hawk, fired. His aim was as true as had been Frank's; and the ray of light disappeared from the surface of the water. The Hawk also was blind now.

Lord Hastings gave an exclamation of dismay.

"Pretty tough," he muttered.

"But we should have guarded against it, sir," declared Jack. "We should have figured that what we could do the other fellow could do also."

"True," replied his commander; "but it's too late now. We'll keep after her. Maybe we can pick her up in the darkness."

"Not much chance," muttered Frank to himself.

But again fortune was to smile on them, although it came near being misfortune.

An hour later, The Hawk having been slowed to a bare five knots, Frank thought he caught the sound of another moving object. He called Lord Hastings' attention, and The Hawk's engine was shut off. Again came the sound, as of a choked automobile engine.

"She's off there, and pretty close," whispered Lord Hastings, with a gesture to port.

"Shall we try a shot in the darkness, sir?" asked Frank.

"No; that would be folly," said Lord Hastings. "There is not one chance in a thousand that the first shot would go home; and then she would be on the move again. Now, from the fact that the sound has come twice from the same place, I judge she is standing still—hoping that we shall run past her."

"If you please, sir, I have a plan," said Jack.

"Let's have it," said Lord Hastings briefly.

"Well, why can't Frank and I take to the boats again. Not one boat this time, but two. We can approach from different directions. One of us can open fire, and if a light is shown aboard, the other can do likewise. Caught between two fires, I believe a light will be shown, that the enemy may try to pick us up. That will betray the enemy's presence to you and you can sink her."

"That's not a half bad idea," decided Lord Hastings after a moment's reflection. "You shall each have a man. Here, Edwards! Williams!"

The two men came forward quickly.

"Williams, you lower a boat and go with Mr. Templeton. Edwards, you accompany Mr. Chadwick. Get your rifles first, men."

The men hurried aft to obey, Frank and Jack in the meantime giving their attention to lowering the boats. This done, all leaped in and rowed in the general direction of the foe.

Upon Jack's suggestion, Frank and Edwards rowed some distance ahead before pointing the nose of their little craft toward where they believed the enemy to be, and then rowed a considerable distance.

"We should be beyond her now," declared Frank, after some further rowing. "We'll double back a bit."

They did so; and five minutes later a dark shape loomed up beside them, so close almost, that Frank could have thrown a rock aboard.

"Cease rowing!" Frank commanded, laying down his own oars.

Edwards did likewise.

"Get your rifle ready," Frank instructed.

Edwards obeyed.

"Now," said Frank, "the first man you see show himself aboard that craft, pick him off. I'll wait for the second one."

"Very well, sir," replied Edwards quietly.

He brought his rifle to bear upon the deck of the enemy and sat quietly, waiting, as the little boat bobbed gently up and down with the swell of the sea.

And he had not long to wait.

A dark shadow appeared aboard the enemy and Edwards and Frank caught the faint glow of a cigar or cigarette as the man puffed upon it. The light from this made his face plainly visible.

"A very indiscreet sort of a gentleman," remarked Edwards. "Here goes, sir."

He pressed the trigger.

A howl of pain rewarded this effort and Edwards smiled grimly to himself.

"Got him," he said cheerfully.

The sound of the rifle brought another figure to the deck. Now it was Frank's turn and he acted instantly. Again there was a faint report and the second man toppled over.

"Two," said Frank quietly.

"Right, sir!" replied Edwards. "All ready for another, sir."

"I guess the next will be along in a minute," said Frank dryly. "Besides, it's about time for Jack and Williams to take a hand in the game."

"Wouldn't want to leave them out all together, would we, sir," grinned Edwards.

"I should say not," replied Frank.

"No, sir; they wouldn't like that."

They waited patiently, but ten minutes passed and no other form appeared aboard the enemy.

"Guess Jack is playing a waiting game on the other side," muttered Frank. "Now, I wonder——"

There came an abrupt interruption to his thoughts.

"Throw up your hands!" came a sharp voice from behind, a trifle to the right. "Surrender or you are dead men!"

CHAPTER IX.

JACK TO THE RESCUE.

Frank and Edwards both whirled hurriedly; and not a fathom's length away rode a second small boat; and standing forward were two men, their revolvers levelled directly at the heads of our friends.

"Up they go, Edwards," said Frank quietly, dropping his rifle and suiting the action to the word. "It's no use; they've got the drop on us."

"They have, sir," agreed Edwards.

His rifle also fell to the bottom of the boat with a clatter and his hands went in the air.

"Good!" said one of the men in the other boat. "You will please keep your hands where they are." He turned to his companion. "Fritz, you row closer, while I keep them covered."

The latter obeyed and soon the two boats scraped.

"Now you will please come aboard my boat," ordered their captor, still keeping them covered. "One false move and you are dead men. Come quickly now."

Frank realized there was no hope for it, so he obeyed without a word. Edwards followed suit.

"Take your places forward there," commanded their captor.

The prisoners obeyed.

"Very good. Now, Fritz, row to the boat."

The latter dipped his oars in the water and the rowboat moved toward the motorboat, at which Frank and Edwards had so recently fired. There the first captor—the man who seemed to be in command—ordered Frank and Edwards over the side.

"Quick, now!" he commanded.

Frank climbed aboard first and as he rose to his feet there was the sound of a shot and the lad felt a bullet whistle past his ear. He dropped to the deck.

"Great Scott! I forgot about Jack being out there," he muttered. "He almost picked me off that time." He raised his voice in a shout. "Hey, Jack! quit that! It's me, Frank! We are prisoners!"

A moment later Edwards clambered over the side of the motorboat and this time there was no shot. Frank felt sure that Jack had heard him and understood the situation.

Now their two captors came quickly over the side and the first turned upon Frank.

"Who were you shouting to?" he demanded.

"Oh, just a friend of mine," replied Frank, with a slight shrug of his shoulders. "He's out there," and the lad waved an arm across the water.

"And what's he doing out there?"

"The same thing we were doing when you found us. Trying to get you fellows."

"Oh, I see," was the reply. "You had us between two fires, eh. It's lucky we put off before you got so close. We heard firing and came back to have a look around."

"Then that's the way you spotted us, eh?" said Frank. "I didn't think you could have got off without my seeing you."

The man made no reply to this, but turned quickly to the other.

"We'll have to get away from here at once, Fritz. Take the wheel."

The latter sprang aft with alacrity, while the first man leaned down and began to tinker with the engine. Frank took a quick step forward and seemed about to leap upon his captor, but the latter turned from the engine and a revolver was in his hand.

"I wouldn't if I were you," he said quietly.

Frank stepped back.

"Oh, all right," he said.

The little motorboat began to move.

The captor raised his voice.

"Hans! Franz!" he called.

There was no answer and after a moment he repeated his calls.

"If you were calling your men, I fear you are wasting time," said Frank quietly.

"What?" exclaimed his captor.

"Exactly," replied Frank. "It was necessary for us to shoot them before you were fortunate enough to find us."

"I see," replied the boy's captor slowly. "Well, I shall have more to say to you about that later."

He again began to tinker with the engine and the motorboat now increased its pace; and then, as the man raised his head to look at Frank, he perceived two dark figures suddenly clamber over the rail and dash toward him.

Frank saw them in the same instant.

"Jack!" he cried.

The German, for such Frank felt sure his captor was, rose quickly to his feet, revolver in hand. He raised it quickly, and pointing it at Jack, who was dashing forward closely followed by Williams, fired.

The distance was so close that a miss would have been impossible and Jack would probably have been killed had it not been for Frank.

The latter sprang quickly forward and seized the German's arm even as his finger pressed the trigger and the bullet went wild. With a muttered imprecation, the German whirled on Frank, reversed his revolver quickly and brought it down on the lad's head.

Frank fell to the deck without a groan and lay still.

At the same moment a shot from the helmsman struck Williams in the chest as he and Edwards dashed toward him and the man fell to the deck, mortally wounded.

Edwards, unarmed, dashed upon the other, but even as he would have grappled with the man, the latter dodged and Edwards went staggering by. Before he could recover himself, the German had clubbed him over the head with his revolver butt.

Thus were three of the friends put hors de combat almost quicker than it takes to tell it. There remained now only Jack, with two against him, both armed.

Jack raised his revolver at the moment Frank fell unconscious to the deck and the German whirled quickly to face him. Both fired at the same moment and both stepped aside as they did so. Jack felt a bullet graze his hand and his revolver fell clattering to the deck. The other, he saw, had not been touched.

Jack sprang forward and grappled with the German even as the helmsman, having disposed of Edwards, took a snap shot at him. The lad stepped forward just in time to escape the bullet.

Realizing now that he had a foe behind as well as in front, Jack seized the first German in a powerful embrace, the man's pistol hand going over his shoulder; and at that moment the German pressed the trigger.

A howl of pain came from the helmsman. The bullet had struck the latter's revolver on the barrel and the force of the shock had momentarily numbed the man's hand.

Jack seized the first German's arm and by a quick twist sent the revolver spinning across the deck, and it passed beneath the rail and into the water.

Now the lad brought rushing tactics into play and pushed the first German the length of the deck before the latter could brace himself. There Jack's eye caught the gleam of the helmsman's pistol and with a quick kick he sent it hurtling overboard also.

But Jack's antagonist was a strong man and the lad knew that he had a hard job on his hands to dispose of him alone, to say nothing of the second man, who, the lad knew, would be fit again in a moment.

But it was no time for indecision; and Jack sprang forward. His right fist shot out with stinging force—a blow that would have ended the battle right there had it landed, but the German ducked and clinched. At this kind of fighting, he was more Jack's match and he seized the lad in a tight embrace.

"Fritz!" called the German, as he and Jack struggled about the deck. "A hand, quick!"

Fritz was now on his feet and he came forward in response to this command. One huge fist he raised, and would have brought it down on Jack's head had not the lad seen him out the tail of his eye and moved his head swiftly to one side.

The blow missed.

Jack, with one hand free for a moment, dealt the helmsman a blow in the face as he swooped past; then again turned his attention to the first man.

The latter now also freed an arm and Jack staggered back from a heavy blow in the face. Blood streamed from a cut over his right eye, blinding him momentarily.

Jack shook the blood out of his eyes with a toss of his head and stepped forward angrily. He had no mind to let his adversary clinch again if he could help it.

As the German rushed Jack met him with a stiff left to the face and the man halted in his tracks with a cry of pain. Jack followed up this advantage with a right-handed blow to the abdomen, doubling the German up like a knife. Then the lad reached his opponent's jaw with a hard left.

The man staggered back and crumpled up in a heap.

"So much for you," muttered the lad, turning just in time to meet the rush of the helmsman, who had now recovered from the effects of Jack's blow and was coming angrily forward.

Now, this second man was even larger and more powerfully built than the first German, and one huge arm warded off Jack's first short jab for the face. Instead of attempting to return the blow, the helmsman grabbed Jack by the arm, and yanked him suddenly forward.

Jack, caught unprepared, went stumbling forward. The helmsman stepped aside and struck heavily at the lad as he reeled past.

Had he taken his time and aimed carefully the battle would have ended right there; fortunately, however, his haste was too great and he only struck the lad a glancing blow.

In spite of this fact, however, the force of it was so great that it staggered the lad. Apparently believing that this one blow would end the fight, the German stepped back to watch the effect of it.

But Jack did not fall. Staggering forward, his hand caught the rail of the boat, where he stood a moment, recovering himself.

The German advanced with a smile on his face. Jack turned to meet him.

Slowly the German came on, his great arms raised awkwardly and then it dawned upon Jack that all that was necessary to dispose of this great brute was a little skill and caution. His head was clear now and he advanced confidently.

The German rushed forward. Jack side-stepped neatly and struck his opponent a heavy blow just above the right ear as he passed. The man turned quickly and just in time to catch a second powerful blow on the forehead. Another man would have gone down, but the German sprang forward ready for more.

And he got more. Jack stood off at arms' length and peppered him beautifully. In vain the German struck out and sought to clinch. Jack dodged his blows and evaded his clasp with ease. And then the lad saw the opportunity he had been awaiting.

In a desperate attempt to clinch, the German exposed his jaw. Jack's right flashed out quickly and then the lad stepped back. His fist had found its mark; and the German staggered back, reeled, swayed—fell to the deck unconscious.

CHAPTER X.

LOST—THE STORM.

Jack now surveyed the field of action with some satisfaction.

"Well, I managed to lay 'em all out at last," he told himself. "Now to see how Frank and the others are."

He hurried first to Frank's side. The latter was just returning to consciousness and raised himself on one elbow as Jack kneeled beside him.

"How do you feel, old man?" asked Jack gently.

"I don't feel so much," was Frank's reply. "Say, that fellow must have given me a pretty good crack."

"He did," said Jack dryly. "I can vouch for that. He landed on your head with that revolver like a ton of brick. Do you think you can stand?"

"I guess so. Lend a hand, will you?"

Jack helped his chum to his feet. Frank staggered a bit at first, but in a minute or two announced that he was fit for whatever might come. He followed Jack aft, where lay the bodies of Edwards and Williams.

Jack passed his hand over Edwards' face and the man stirred feebly.

"Water, Frank," said Jack.

Frank hurried forward again and returned in a moment with water. This Jack sprinkled over Edwards' face. Five minutes later Edwards sat up.

"What's the matter?" he asked.

Jack explained.

"I remember now, sir," said Edwards, trying to smile. "And did you lick 'em?"

"I did," said Jack.

"And Williams, sir? How is he? I saw him go down just before I went under."

"We'll see," replied Jack briefly.

He led the way to where Williams still lay prone, Frank and Edwards following.

Jack bent over the man, then placed a hand over his heart. Then he got slowly to his feet.

"Is he——," began Edwards.

"Dead," replied Jack quietly.

For a moment there was silence; then Edwards spoke brokenly.

"The best shipmate a man ever had, sir."

He knelt beside his dead companion and tears streamed down his face. Jack and Frank did not speak as he mourned silently for some minutes. At last Edwards got to his feet.

"War is war, sir," he said quietly.

He moved aft.

"Well," said Frank, "I guess we may as well be getting back to The Hawk. Lord Hastings will be worried."

"Right," said Jack. "You take the wheel. I'll try and coax the engine along."

They took their respective places.

"Which way, Jack?" called Frank.

"By Jove! You know as much about it as I do," was the reply. "I don't know where we are."

"Must be off to the left," declared Frank. "We'll steer that way, anyhow."

"All right," said Jack.

The engine began to sputter and directly the motorboat moved.

"We may as well go this way as another," Frank shouted to make himself heard. "It'll be daylight soon, anyhow, and we can probably pick up The Hawk."

"We'll go slowly, at all events," said Jack.

For half an hour the little craft forged slowly ahead, all three aboard keeping a sharp lookout for The Hawk.

Suddenly a breeze sprang up. It blew lightly at first and then with more and more violence.

"Looks like Lord Hastings' gale was about to materialize," shouted Jack.

"Guess this is it all right," replied Frank.

Edwards now came aft and took his stand by Frank.

"Want me to take the wheel, sir?" he asked.

"Guess I can handle it all right," replied Frank.

"Very well, sir, only I thought you would rather be forward with Mr. Templeton."

There was an odd note in his voice and Frank glanced at him inquiringly.

"What made you think that?" he asked sharply.

"Only," replied Edwards, "only because this is liable to settle things for all of us."

"You mean the storm?" asked Frank.

"Yes, sir."

"You think it will be severe?"

"Very severe, sir. I have sailed the seas longer than you have, sir, and I recognize the signs."

"And you don't think this craft can weather the storm?"

"I am afraid not, sir. Of course there is always a possibility, and by running with the storm we have, of course, a fighting chance; but that's all we have, sir, a fighting chance."

"It is as much as we have had many times before," replied Frank.

"Very well, then," to Edwards, "you may take the wheel. Your advice is to run before it?"

"Yes, sir, at full speed."

"Your advice shall be taken. We'll keep the engine going and the steering is up to you."

"Very good, sir."

Edwards took the wheel and Frank made his way forward.

"Hello," said Jack. "Thought you were going to do the steering."

"I was," replied Frank, "but Edwards seemed to think he could do better and I guess he is right. He says we are in for a bad gale."

"He's right," replied Jack. "I've seen the signs before. You may remember I lived on the ocean. Yes, we're in for it, I'm afraid. All we can do is run."

"That's what Edwards said."

"It'll be daylight in less than half an hour," Jack continued. "That will help some. If it will hold off that long, I'll feel better."

And the gale did hold off.

A faint gray streaked the east, making more plain the seriousness of their situation. The clouds hung heavy and low and it took no mariner to tell that a storm was brewing.

Gradually the wind increased and the little motorboat tore along before it. Now the swell of the sea became heavier. Waves rolled higher and higher and the little craft first wallowed in the trough of the sea and then climbed the gigantic waves.

"No wonder people get seasick," Frank muttered to himself.

The wind increased in violence until it blew a hurricane, but still the little motorboat did not falter; it bore on as bravely as before, climbing wave after wave swiftly and unerringly. Edwards, at the wheel, was giving a splendid example of seamanship.

A mountainous wave, greater than the rest, descended upon the motorboat and broke over it, drenching all on board to the skin. The wind whistled overhead and the air grew icy cold. Frank shivered, as he held fast.

"Br-r-r," he said. "Right now it would feel awfully nice to be ashore. I wonder what of Lord Hastings and The Hawk?"

At the same moment, Lord Hastings was wondering what of them.

For hours and hours, it seemed to the two lads, the little craft battled the storm, at each moment seeming in imminent danger of capsizing; but always the master hand of Edwards at the wheel righted the little craft and it dashed away in the gale.

"Great Scott!" cried Frank, raising his voice to a shout to make himself heard above the terrible roaring of the wind, "we can't stand this much longer."

"You are right," declared Jack. "We are liable to be swamped at any moment."

As each wave descended upon them, breaking over the little boat, Frank was confident that the end had come. It did not seem possible that the craft could withstand another. But each time the little boat seemed to brace itself for the shock and a moment later would ride high to safety.

Edwards, at the wheel, had lashed himself fast, that he might not be swept overboard; and once, soon after the storm had descended, he was startled.

Something soft touched his feet; and taking his eyes from ahead long enough to look down, he saw that the object was the body of Williams, which the water had washed over the deck to him.

His hands fast, as they were, he could not stoop down to touch the body as he gazed at it mournfully; then another wave descended, and when it had gone, Williams' body was no longer in sight.

"Good-bye, old friend!" Edwards shouted after it. "Good-bye! I may be with you soon. If I could have reached down I would have shaken hands with you once more before you went away."

Another gigantic wave swooped down and he gave his attention to keeping the boat's head right.

At last, when it seemed that the storm would never end, it broke suddenly. As if by magic there was a calm, and bright sunlight streamed down from above. The gale was over. The motorboat and its crew of three were safe.

Frank and Jack clasped hands.

"Safe once more," said the latter quietly.

Suddenly the little craft pitched violently. Frank turned a quick gaze aft to the wheel where he made out the reason for this sudden lurch.

Completely exhausted by his recent experience, Edwards had lapsed into unconsciousness once the strain was over. No hand grasped the wheel and the motorboat pitched this way and that in the trough of the sea.

Frank made his way aft as rapidly as possible and took the wheel. Jack shut down the engine and followed him. He poured water over Edwards' face and directly the latter sat up.

"Funny I had to keel over like that," he said grinning feebly. "Don't know what's the matter with me. Must be getting old, I guess. Never happened before."

"Here," said Jack, "you come forward with me and rest awhile. You're about done up."

The sailor protested; but Jack had his way, and a few moments later, in the little cabin, Edwards was fast asleep. Jack returned aft to discuss the situation with Frank.

"Well, what now?" asked the latter. "Where are we going to find Lord Hastings?"

"I imagine the best thing for us," said Jack, "is to return to Bantry Bay. If The Hawk weathered the storm, Lord Hastings will put in sometime to-day."

"I suppose that is best," agreed Frank. "Let's be on the move."

The head of the motorboat was brought about, and gaining his bearings from a compass in the cabin, Jack shaped his course.

"A four or five hour run," he said to Frank, in giving him the proper directions.

He glanced at his watch. "Six o'clock. Well, we shall be there before noon, anyhow."

He returned to his place at the engine and the motorboat headed toward the British coast.

CHAPTER XI.

ON THE HUNT.

"Isn't that The Hawk?"

It was Jack who spoke. He had left his engine and made his way aft, for he had caught sight of another craft in the distance.

Frank peered ahead.

"I should say it was built along the same lines as The Hawk," he replied, "but what's the matter with her?"

Something was wrong, as both boys could see. The craft ahead, whether The Hawk or not they could not yet distinguish, was plainly in distress. She wallowed in the sea, apparently without a hand to guide her.

"Something wrong aboard, sure," declared Frank. "Little more speed, Jack."

Jack sprang back to his engine and soon the motorboat was dashing through the water at full speed.

Jack left the engine to run itself and made his way forward as far as possible, where he stood gazing at the craft ahead. At last he was able to make out the name of the craft.

"The Hawk!" he cried.

It was The Hawk and she was plainly in distress. As the boys drew nearer, they were unable to make out a sign of life aboard.

"Maybe they have all been washed overboard," Frank called to Jack.

Jack made no reply. He had begun to fear so himself.

Suddenly he uttered a loud cry.

"I can see some one aboard," he cried. "He's stretched out on the deck. Looks like he might be dead."

"Who is it?" Frank shouted back.

"I can't make out yet."

He peered forward eagerly and anxiously; and five minutes later he cried out again:

"It's Smith."

Smith was another of the crew.

"Can you see Lord Hastings?" shouted Frank.

"No."

The two craft were less than a hundred yards apart now and still Jack could make out but a solitary figure aboard, that of Smith, stretched out at full length aft.

The boys closed up the remaining distance quickly and the two boats scraped alongside each other. Pausing only long enough to lash the two together, Frank and Jack sprang aboard The Hawk.

Quickly they glanced about. There was Smith and no one else in sight. Frank stooped over him.

"He's breathing," he said.

He hurried to the side of the boat, and leaning over, filled his cap with water. This he sprinkled in Smith's face and the man stirred.

Jack, in the meantime, had gone into the little cabin and a startled cry now came to Frank's ears.

He hurried to his friend; and there, in the cabin, the boy stood over the prostrate form of their commander. The latter lay still and white and Frank stared at him with a great fear in his heart.

"Is he dead?" he asked in a hoarse whisper.

"I don't know," said Jack slowly. "He doesn't seem to be breathing."

Frank knelt down and placed a hand over Lord Hastings' heart.

"Yes, he is," he cried excitedly. "His heart is beating. Water, quick!"

Jack dashed away in response to this command and was back in a moment with his cap filled with water.

This he poured over his commander, while Frank bathed his head; and soon these efforts were rewarded.

Lord Hastings stirred, breathed a long sigh and moaned. Five minutes later he opened his eyes and tried to sit up.

"Lie still, sir," commanded Frank.

Lord Hastings let his eyes rest on the lad's face, tried to say something, attempted to move, then fell back with a long sigh.

Again Frank was alarmed. He bent over his commander and placed a hand over his heart. Then he arose with an exclamation of satisfaction.

"He's sleeping," he said. "Let's get to shore as soon as possible."

Jack hurried away. First he returned to the other craft and assisted Edwards aboard The Hawk. Then he went to the engine, Frank took the wheel and they headed for Bantry Bay at full speed.

It was still before noon when they entered the bay and came to anchor in the midst of the motorboat fleet. The lads had Lord Hastings removed ashore immediately and listened to the diagnosis of the surgeon with bated breath.

"Nothing serious," said the surgeon, much to the lads' relief. "He's been knocked unconscious in some way. Something must have struck him a hard blow across the head. All he needs is perfect quiet for a week."

"He'll get it," declared Jack, "if I have to sit on him for that length of time."

"And if I have to help you hold him down," Frank agreed.

For the next week the boys gave their undivided attention to caring for their wounded commander. Each day, after the first, Lord Hastings grew stronger. On the third day he wanted to get up, but the surgeon would not hear of it.

"Seven days in bed," he declared. "Not a second less; and two more days before you can move about much."

"Yes, but look here, Doc," said Lord Hastings. "I've work to do. I've got to get back into harness."

"And two weeks exactly before you can get back in harness," declared the man of medicine.

From this ultimatum he would not swerve.

At the end of the first week Lord Hastings was for disregarding the surgeon's orders and getting back into harness anyhow; but Jack and Frank would not hear of it.

"Might just as well get well, first, sir," declared Jack.

Lord Hastings glared at him.

"How about you?" he demanded. "How would you like to stay around like this doing nothing? You couldn't sit here for five minutes. I know you."

"You may be right, sir," agreed Frank. "But you are older than I am, sir, and should have more patience and fortitude."

Lord Hastings was forced to smile at this rejoinder.

"You see, sir," said Frank, "I can remember some of the things you have said to me."

"I see," agreed Lord Hastings. "I guess, then, that I shall have to remain here, if for no other reason than to set a good example for you."

"That's right, sir," declared Jack. "If you didn't, there would be no living with Frank."

"Oh, I don't know," said the latter. "I can remember one time when you were in bad shape that I had to threaten to lick you to keep you in bed."

"Well, that's different," said Jack. "I——"

"Well, let's talk about something cheerful," said Lord Hastings. "Germans or anything like that."

And so the conversation was changed.

When the two weeks had come to an end Lord Hastings proceeded to get back in harness immediately.

"I've been here long enough," he told the boys. "Back to The Hawk again now."

And back to The Hawk they went that day.

Aboard The Hawk Lord Hastings made a careful inspection and then left the lads, while he held an interview with the British commanding officer in charge of the motorboat flotilla. When he returned he had a smile on his face.

"Good news," he said, as he came aboard.

"What, sir?" asked Frank.

"Action to-night, sir?" demanded Jack.

"Better than that—for you boys," replied Lord Hastings. "Action, and at once."

"Where?" asked Frank.

"Around the same neighborhood we were in before."

"Good," declared Jack.

"And more important prey, this time," continued Lord Hastings.

"Submarines?" asked Jack.

"Well, that's what we expect," replied Lord Hastings. "We hope to be fortunate enough to find one or two."

"When do we start, sir?" demanded Frank.

"As soon as the Glasgow comes along."

"The Glasgow, sir? You mean the steamship Glasgow?"

"Exactly. It appears that passengers have been warned not to take passage on the Glasgow. A warning has been circulated through the newspapers, the same as was done before the Lusitania sailed and was sunk. This naturally leads to the belief that the Germans are planning to torpedo the Glasgow. We are to be on hand to see that this does not happen."

"I see, sir," replied Frank. "Is it just The Hawk, sir?"

"Well, no," replied Lord Hastings. "The Hawk and nine other motorboats."

"A regular fleet," remarked Jack. "I suppose the idea is for us to trail in behind the Glasgow?"

"Exactly. You see the submarine, nine times out of ten, lying in wait for its victim, will come to the surface a short distance ahead of the steamer. Now, in view of the furore that the sinking of the Lusitania caused in neutral countries, it is hardly to be expected the Glasgow will be torpedoed without warning."

"But just how do we get at the enemy, sir?" demanded Frank.

"I'm coming to that. When the submarine comes to the surface and gives warning for passengers and crew to leave the ship, we shall sneak out from behind at full speed. Before the submarine can submerge, we shall be close enough to get her. That's why we carry such heavy guns. One of us is bound to get her."

"I see," said Frank. "Of course if the submarine could submerge in a moment, it wouldn't be possible."

"Exactly," agreed Lord Hastings.

He led the way to the rail.

"See," he said, waving a hand in the direction of the others of the motorboat fleet, "they are all getting ready for action."

It was true. There were signs of great activity aboard some of the other little vessels. "Just overhauling to see that everything is shipshape," said Lord Hastings. "We may as well do the same."

The next hour was spent in minute inspection of every part of the little craft and then Lord Hastings pronounced himself satisfied.

Hardly was the work completed, when Frank perceived a dark smudge upon the distant horizon.

"Vessel of some kind, sir," he reported to Lord Hastings.

Lord Hastings gazed long and earnestly; and directly the shape of a large ship loomed up.

"The Glasgow," he said quietly. "All ready, boys. Time to get busy."

CHAPTER XII.

THE FIRST VICTIM.

As the steamship Glasgow drew nearer, the signs of activity among the various units of the motorboat fleet became more acute. The little craft darted hither and thither, finally dividing into two sections, one section on each side of the channel through which the Glasgow steamed toward them. When the big steamship had steamed past, the ten little boats fell into line behind her, moving swiftly forward, two abreast.

Apparently the commander of the Glasgow, Captain Sawyer, had been informed that he was to be provided with an escort, for only the fluttering of a few signal flags from the Glasgow and from the motorboat Lion, which carried Lieutenant Commander Thompson, in charge of the mosquito fleet, betokened a greeting.

The Glasgow swept majestically past, not pausing in her stride. From the decks hands were waved and handkerchiefs fluttered toward the little vessels below, the passengers aboard leaning over the rails and speculating idly upon their presence.

The two foremost motorboats were The Hawk and the Lion, commanded by Lieutenant Commander Thompson and Lord Hastings. The others followed close behind.

Jack and Frank had watched all this maneuvering with great interest; and now that the flotilla, in perfect formation, was proceeding straight ahead, Frank turned to his commander with a question:

"And about where do you expect to pick up the enemy, sir?" he asked.

"Hardly more than twenty miles out—certainly not more than two hours," was the reply.

The motorboats followed closely in the wake of the big steamship. Although they were, of course, plainly visible from the steamer, and could possibly be seen from the sides, it was hoped that the enemies' submarine would take a position directly in front of the Glasgow when she accosted her. This would shield the motorboats from sight.

The Glasgow and its bodyguard were now out of sight of land. The sun shone brightly and the day was perfectly calm. There was scarcely a ripple upon the smooth surface of the sea.

Below, aboard the Glasgow, the passengers were at dinner. They were laughing and joking among themselves.

Aboard the motorboats all was peacefully quiet. The men not on duty were idling about and talking.

Suddenly Edwards, who stood forward on The Hawk, caught the peculiar fluttering of the signal flags aboard the Glasgow.

"Glasgow signalling, sir," he reported to Lord Hastings.

Lord Hastings quickly drew the attention of Commander Thompson to the Glasgow's signals, at the same time deciphering them for Frank and Jack.

The first signal read:

"Small vessel dead ahead."

Commander Thompson flashed back his response:

"Submarine?"

"Can't make out yet," was the answer.

There was some further wig-wagging; and then the need for this means of communication suddenly ceased.

There came a sharp blast from the Glasgow's horn and the big ship slowed down abruptly. Then came the sound of a shot from dead ahead and there was a splash between the Glasgow and The Hawk.

"The enemy!" exclaimed Lord Hastings.

Aboard each of the small motorboats every man sprang to his post. Soft commands carried back and forth across the water, while the signal flags of the Glasgow continued to flutter.

Then, even as Lord Hastings received from the Lion the command to advance, he read the last signal of the Glasgow.

"Submarine has halted us," it read. "Dead ahead."

The motorboat fleet came to life upon the instant. Again it divided into two parts, one passing on each side of the Glasgow, and darted forward toward the enemy.

Aboard each the forward guns were manned, the gunners ready to fire at the word.

On the Glasgow all was confusion. Passengers, attracted by the sound of the shot from the submarine, sprang from their tables and dashed on deck. There, as they made out the submarine, they turned pale. Only the reassuring voices of the officers averted a panic.

Then the passengers turned their attention to the fleet that was now passing around the big liner to the attack.

Rapidly the little craft sped forward and before the submarine commander had divined their presence, they were swooping down upon him, seemingly from all directions. Stunned at this unexpected arrival and before he could give a word of command, The Hawk unloosened her forward gun.

The shell went wide, but it brought immediate action from the submarine commander. Evidently he had no mind to try and torpedo the little craft, realizing, perhaps, that did he sink one the other would destroy him.

Motioning the other three men on deck before him, he sprang toward the little conning tower, bent on flight.

At this juncture the Lion came within range and her forward gun spoke loudly. The shell kicked up the water a few yards from the submarine.

"Hoorah!" came the British cry.

"A little soon to cheer," muttered Frank to himself, as he stepped forward to take his second shot at the submarine.

"Boom!"

The gun spoke sharply.

Ahead there was a terrible crash. The German submarine seemed to soar in the air like a skyrocket, and came down in a thousand pieces.

Frank's one well-directed shot had ended the battle.

Then a mighty cheer went up from the men of the mosquito fleet, in which the passengers aboard the Glasgow joined with a will.

Jack sprang forward and gave his chum a resounding slap on the back.

"That's what I call shooting," he declared fervently.

"Good work, Frank," said Lord Hastings quietly, stepping forward. "An excellent shot."

Masses of wreckage floating upon the surface of the sea were all that was left of the German submarine, with here and there a few floating bodies. Soon these disappeared and there was nothing to indicate that an under-sea craft had so recently been near.

From aboard the Lion, Commander Thompson signalled his compliments to The Hawk.

"And now I suppose we will go back again," said Frank to Lord Hastings.

"Well, no," was the reply. "The Glasgow is not safe yet. There may be other submarines in these waters. I should say that we shall escort her all of a hundred miles."

"What I would like to know," said Frank, "is why her commander, instead of trying to escape at once, didn't launch a torpedo or two. He might have disposed of one of us."

"But the others would have surely done for him," said Lord Hastings. "He probably figured he could submerge before we could hit him."

"He guessed wrong that time," declared Frank.

"Rather," agreed Jack with a smile. "There is no use talking, Frank, you are some boy when it comes to shooting."

All that afternoon the motorboat flotilla trailed the Glasgow; but until nightfall no other German submarine had appeared. An hour after nightfall, Commander Thompson gave the command to put about and return.

Slowly the little craft came about and started back toward Bantry Bay. Behind them now, the Glasgow, safe at last, steamed rapidly away, bound for the distant port of New York, and "home," said Frank to Jack.

"Do you wish you were on her," asked his chum curiously.

"No," replied Frank, slowly, "unless I was sure I would find my father waiting for me when I reached there. However, I am having a pretty good time on this side and I know that I shall return safely some day."

The Hawk, last in line, made her way back slowly.

An hour after the lights of the Glasgow had faded from view, Frank, glancing forward, was unable to make out the distant light of a single of the other motorboats. He called Lord Hastings' attention to this fact.

"Is that so?" exclaimed his commander in some surprise. "I had no idea we had been going so slowly. We'll step out a bit."

He issued a command, and the speed of The Hawk increased. But still, after an hour, they had failed to come up with the others.

"Well, it's nothing to worry about I guess. We know the way back as well as the others; besides, there is no particular hurry."

Accordingly The Hawk continued at rather slow speed.

Half an hour later, Frank, forward, made out a dark hulk lying low in the water a short distance ahead. He immediately called Lord Hastings' attention to the object.

The latter acted quickly.

"Extinguish all lights quickly," he called sharply.

The order was obeyed, and at a second command, The Hawk was slowed down so that she was barely moving.

"What's the matter, sir?" exclaimed Jack, in great surprise.

"Matter is that there is a submarine dead ahead of us," was his commander's reply.

"You mean that dark object there?"

"Yes."

"And are we going to sink her, sir?" asked Jack.

"We'll have a try at it," was the reply. "In this darkness we can go very close without fear of being seen, The Hawk is so small."

Fifty yards from the submarine, which lay quietly in the water, The Hawk came to a stop and the forward gun was made ready for action.

"Funny there isn't some one on deck," muttered Frank.

"By Jove! So it is," declared Lord Hastings. "Must be something wrong. I wonder what?"

"I have it, sir," declared Frank. "It's one of the vessels that those other motorboats—the ones we sunk—were to have reported to."

"I believe Frank is right," agreed Jack. "It probably comes to the surface here every night, awaiting their return."

"In that event the chances are that most every one aboard is asleep," remarked Lord Hastings.

He gave the command for The Hawk to proceed.

"What are you going to do, sir?" asked Frank.

"See if we can't capture her," replied Lord Hastings quietly.

Frank gave a low whistle. It was a plan after his own heart, but he was keenly sensitive to the danger that it involved.

"Very well, sir," he said quietly.

"This," declared Jack, manifesting a show of enthusiasm, "is where we have a little fun."

CHAPTER XIII.

A DESPERATE VENTURE.

There was not a sound aboard the submarine as The Hawk grated alongside. To climb aboard the silent vessel, which lay so low in the water, was a simple task. Lord Hastings went first and Frank and Jack followed in order. Behind the latter came Edwards and behind him three sailors, Allen, O'Brien and McDonald.

For a brief moment they stood silently upon the deck, each with a revolver in his hand. Then Lord Hastings led the way to the conning tower, which was open, and descended. The others were close behind him.

At the foot of the companionway Lord Hastings paused again, straining his ears for a sound. None came. He motioned the others to follow him and led the way aft.

At the extreme afterpart of the vessel he paused before a door on the port side. From within came the sound of voices.

Lord Hastings laid a hand on the knob and surveyed those behind him.

"All ready?" he asked.

"Ready, sir," replied Jack quietly.

With a sudden movement Lord Hastings jerked open the door and stepped quickly within.

"Hands up!" he called sharply.

Four men sat at a table in what appeared to be the commander's cabin. They looked up from their game at Lord Hastings' gruff command and seeing but a solitary figure, all dropped their hands to their side.

"Hands up!" commanded Lord Hastings again.

Instead of obeying this command, one man produced a revolver, shouting:

"There is only one! Shoot him!"

But Lord Hastings' revolver spoke first and the officer tumbled over. The other three had now drawn their weapons and one fired at Lord Hastings. The shot went wild and Lord Hastings dropped him with a second well-directed bullet.

At this moment Jack and Frank sprang into the room. They saw Lord Hastings confronted by two enemies and they acted instantly and before the Germans could do so.

The revolvers of both lads spoke simultaneously and both Germans dropped to the floor.

Jack sprang back to the door.

"Stand guard there, men!" he cried. "There may be more of them."

He jumped back to Frank's side again, fearing that one of the fallen men might arise and return to the fray. But these fears were groundless. All four were beyond human aid, as Lord Hastings found after gazing at each sharply.

"Poor fellows," he said sorrowfully, "but it was their lives or ours, and they wouldn't yield. Oh, well——" he broke off with a shrug of his shoulders and turned to the lads.

"Search the vessel," he commanded. "There are probably others aboard."

Jack and Frank hurried away in response to this command. They went through the submarine from stem to stern, but nowhere were they able to find another living soul.

"Looks like those were the only ones aboard," remarked Jack.

"It does," agreed Frank. "Maybe the men in the motorboats were part of their crews and they have been lying about here all these days waiting for them to return."

"Well, I can't guess the answer," said Jack. "But certainly there is no other German here."

They returned and reported to Lord Hastings.

"Very well," said their commander. "Then the best thing we can do is to try and work this submarine back to port. It is an important capture."

"If you please, sir," said Jack. "I believe I can suggest a better plan than that."

"And that is——" prompted Lord Hastings.

"To assume the identities of these German officers, sir. Or not necessarily to assume their identities, but just to take charge of the vessel as if we had been duly commissioned by the German government. Then we can seek out the enemy's naval base and perhaps gain information of importance."

Lord Hastings looked at the lad in amusement for some moments before he replied:

"By Jove! You and Frank here do turn up some of the most remarkable ideas I have ever heard!"

"Then you don't think much of the plan, sir?"

"I think so much of it," replied Lord Hastings, "that I shall act upon it at once."

Now it was Frank's turn to show his enthusiasm.

"Hoorah!" he cried.

"That is," Lord Hastings qualified his statement, "I shall act upon your plan if Mr. Chadwick here can restrain his enthusiasm. Otherwise, I would be afraid to undertake the venture."

"I'll restrain it, sir," declared Frank, subdued.

"Good! See that you do," returned Lord Hastings. "Some of these days that enthusiasm of yours will get us all into trouble."

"And what shall we do with these men, sir?" asked Jack, indicating the fallen Germans.

"Overboard with them, I suppose," returned Lord Hastings. "It's where I expect to go when my time comes. It's as good a grave as another."

"And shall we take their uniforms, sir?"

"Yes. It may spare some explaining."

And thus it was arranged.

Two hours later, following a thorough exploration of the submarine, Lord Hastings announced that he could navigate it without trouble.

"Fortunately," he said, "I find that it will be possible for two men to handle the engine room. We three and Edwards will take our turns at the wheel and doing whatever else is to be done, relieving in the engine room when it is necessary. Of course we are short-handed, but I believe we can pull through. Perhaps, if we are fortunate enough to fall in with one of the enemy, we can borrow a few men. We can concoct some story that will pass muster and thus account for the loss of the others of our crew."

Jack smiled.

"I guess it can be done, sir," he replied.

The dead Germans had been buried by this time and the three British officers had donned their uniforms, which, fortunately, were not bad fits.

"To tell the truth, I don't care much about these uniforms," declared Frank, "but if they are going to help out any I suppose I can stand mine for a while."

"You don't necessarily have to be in love with them," responded Jack.

"And now, sir," said Frank, "would it not be well to be moving? There may be some of these men prowling about the sea some place and they may return."

"Yes; there is no use lingering here," replied Lord Hastings. "Are the men at their posts?"

"Yes, sir."

"Good! Then you may give the signal to submerge, Mr. Templeton."

"I can give it all right," grinned Jack. "But I don't see what good it will do unless I obey myself."

"True," laughed Lord Hastings. "I had forgotten about the tanks. We shall have to take turns looking after them also."

"I'll attend to them this time," said Jack, and took himself off.

Directly the submarine began to sink slowly and at a depth of ten fathoms Lord Hastings called a halt. Then he signalled the engine room for twelve knots.

"Just where are we bound, sir?" asked Frank.

"Well," said Lord Hastings, "the Germans are understood to have established a naval base at Ostend and I have shaped my course for that port."

"And what are we to do when we get there?"

"Events will have to shape themselves," declared Lord Hastings. "It is impossible to foretell anything."

Jack re-entered the room at this moment, and the three held a consultation, Edwards meantime steering the course that Lord Hastings had given him.

And so the submarine continued on its course beneath the sea for the rest of the night, running slowly.

At eight o'clock in the morning, Lord Hastings decided to go to the surface for a look around. He stopped for a moment, however, just below the surface, with the periscope protruding slightly above the water and took in his surroundings.

In the distance he made out a coast line, which, according to his calculations, should be the coast of Belgium.

"We should not be more than an hour's run from Ostend," he told the lads. "We'll continue on the surface."

The submarine was brought clear of the water and continued on her way.

But there was to be no need of the submarine putting into Ostend. Half an hour after the vessel had been brought to the surface, Frank, who was alone for the moment upon the bridge, made out a second submarine approaching. Quickly he summoned Lord Hastings and Jack.

"Well," said Lord Hastings, "here is where we have to do some tall talking, as the Americans would say. He's headed directly for us."

It was true. The submarines were approaching each other rapidly.

The enemy slowed down, and in response to Lord Hastings, the captured vessel did likewise. A voice from a figure on the bridge of the second vessel came across the water.

"Who are you?"

"U-16," answered Lord Hastings, who had gone through the former commander's papers carefully, "Bernstorff, commanding."

"Bernstorff," came the surprised response. "Where is Captain Tarlenhein?"

"If you will come aboard, I will explain," shouted Lord Hastings.

"Very well."

A few moments later a small boat left the side of the other vessel and came toward the U-16.

"Now, boys," said Lord Hastings quietly, "keep a tight rein on yourselves and leave the talking to me. Say nothing unless you are addressed. It would not do for us to be tripped up. We would all be put to death as spies."

The boys nodded their understanding of this order.

"We'll be as mum as a couple of oysters, sir," declared Frank.

"I wouldn't know what to say, anyhow," agreed Jack.

"Sh-h-h," whispered Lord Hastings. "Here he comes."

The small boat scraped the side of the U-16 at this juncture. A man in the full uniform of a German lieutenant commander stepped aboard. Lord Hastings advanced to meet him with extended hand.

Jack and Frank followed their commander closely.

CHAPTER XIV.

WITH THE ENEMY.

"I am Captain Bernstorff," said Lord Hastings quietly, "and you?"

"Lieutenant Commander Von Rosten, sir," replied the other, who could not have been more than twenty-five years of age.

"Von Rosten, to be sure," replied Lord Hastings, affecting to recall the name. "Allow me to present my friends, who are at present acting as my officers."

He beckoned to Frank and Jack to approach.

"Lieutenant Papen," he said, introducing Jack; "and Lieutenant Bohring," indicating Frank.

The three acknowledged the introductions and then Lord Hastings continued:

"I suppose you are wondering how I come to be in command of the U-16?"

"I am, sir," was the reply.

"And also," continued Lord Hastings with a smile, "you are no doubt wondering just who I am anyway?"

"I must confess to that, too," answered the young German.

"Well, I can explain in a very few words," said Lord Hastings quietly. "In the first place, I carry a number—you know what I mean?"

The German nodded.

"The secret service," he said quietly.

Lord Hastings gave him a glance of approval and the young man flushed.

"Exactly," replied Lord Hastings. "My friends here also carry numbers. They are young, as you see, but they have proved themselves more than once in His Majesty's service."

The young German bowed again.

"Now," continued Lord Hastings, "I shall take up the little matter of how I happen to be in command of the U-16 and the unfortunate fate of Captain Tarlenhein."

"Fate!" exclaimed Von Rosten.

"It is only too true," muttered Lord Hastings sorrowfully. "But he died as a loyal servant of the Emperor. I shall explain."

"If you will," said the young German.

"Under command of Captain Tarlenhein," said Lord Hastings, "the U-16, as you may possibly know, has been in the Irish Sea, and, at one time or another, off the mouth of the Thames. Whether you knew it or not, Captain Tarlenhein also carried a number. There was work to be done in England.

"Of course, we already had our agents there—in fact, I was one of them, and my two friends here. We were instructed to report to Captain Tarlenhein aboard the U-16 at a certain time. We did so, the vessel at that time lying off the Thames. Captain Tarlenhein had other instructions for us. We went ashore again and there encountered trouble. We were captured.

"In London we were being taken to The Tower, when we all made a break for liberty right in the middle of the city. Captain Tarlenhein was shot down. The rest of us escaped. Through the instrumentality of my peculiar resemblance to a British naval officer, we overcame numerous difficulties, although my young friends here almost came to grief. It was here that my striking resemblance to this British officer of whom I speak enabled them to get away. We were, of course, dressed in British uniforms, but the haste of another agent of the Emperor almost caused our undoing."

The German officer had followed this account with interest. Apparently he was much wrapped up in the narrative. He clenched his hand as Lord Hastings paused.

"And who was this agent?" he demanded.

"An Englishman," replied Lord Hastings slowly. "An Englishman known as Davis. He almost spoiled it all. However, we at length managed to escape in spite of Davis—I don't know what has become of him—and made our way, after many perils, to where the U-16 still awaited the return of its commander.

"And what was our surprise, when we went aboard, to find it occupied by two British officers and several British sailors. Fortunately for us, these British officers—lazy dogs—were sleeping at their posts and we pounced upon them and tumbled them overboard, all but three; whom we kept as a crew, our own men having been taken prisoners by the enemy. That was only yesterday, and here we are."

Lord Hastings paused.

"You have indeed had a hard time," said the young German. "But I am glad to know you, all three of you. About this man Davis. I have a man aboard my ship who might possibly be the same. He says his name is Davis, and he is an Englishman; but I have placed no faith in his story. He is a shifty-eyed scoundrel. I picked him up off the British coast about two weeks ago."

"He is undoubtedly the same," said Lord Hastings. "Also his story probably is true. I can vouch for the fact that he carries a number, and that he was recently in England."

"Will you and your men come aboard my vessel?" invited the young German. "I should be pleased to have you look at this man Davis. I have him in irons."

"We shall be pleased," Lord Hastings accepted. "But first we must go below and tie up these English sailors. We don't want them to get away."

The young German bowed, and Lord Hastings, Frank, and Jack went below.

Here Lord Hastings called the men to him and in a few words explained the situation. The men consented to be bound and the three tied them up, for, as Lord Hastings said, it was just as well to keep up appearances.

Before returning on deck Lord Hastings also issued a few sharp commands to Jack and Frank.

"Just keep your nerve and everything will turn out all right," he said.

"But Davis," exclaimed Frank. "He is likely to betray us."

"Don't you believe it," said Lord Hastings. "Von Rosten doesn't trust him very much and Davis will be sharp enough to know it. That's why I want to appear to be doing him a good turn. Besides, it will throw both of them off the track."

"I see," replied Frank. "I wouldn't have thought of that, sir."

Lord Hastings again led the way on deck and informed the young German commander that they were ready to accompany him aboard his vessel. The latter motioned them into the small boat ahead of him.

Ten minutes later they were all seated in Captain Von Rosten's own cabin. The German summoned his first officer.

"Have the prisoner brought here," he commanded.

A few moments later, Davis, still in irons, stood before them. He gave an exclamation of surprise when he glanced at the three Englishmen, and all knew that he recognized them. Lord Hastings thought it would be well to get in the first word.

"I see you recognize us," he said sharply.

"Well, I guess I do," returned Davis. "You are——"

"Never mind who we are," interrupted Lord Hastings. "Enough for you to know that you almost spoiled everything."

"What's that?" demanded Davis. "I almost spoiled everything? Me?"

"Yes, you," returned Lord Hastings quietly. "You and the Baron Blosberg, with your impatience. I don't suppose you know that we carry numbers, eh?"

"I didn't know you did," replied Davis. "These other two here," indicating Jack and Frank, "I surmised did, or else I was fooled. But the last time I saw you you wore a British uniform and seemed to be perfectly at home."

"Fortunately for the rest of you," commented Lord Hastings dryly. "Otherwise none of you would be here now."

Davis was apparently convinced.

"And did you have success?" he asked. "Have you solved the mystery of the——"

"Vanishing submarines?" interrupted Lord Hastings. "Yes. We have solved it."

Von Rosten sprang to his feet.

"Is it true?" he exclaimed eagerly. "The mystery has been solved?"

"It has," replied Lord Hastings quietly.

"And you can suggest means for overcoming it?"

"I can," replied Lord Hastings, and added: "At the proper time and place."

Von Rosten sat down and indicated Davis.

"Then you can vouch for this man?" he asked.

"Yes," replied Lord Hastings. "And I should be glad if you would release him. He is a traitor to his country and something of a bungler, but I can make use of him."

"Very well, sir," returned Von Rosten. "Then I shall turn him over to you."

"If you would be so kind," said Lord Hastings.

The German again summoned his first officer.

"Take the irons off this man," he commanded.

The first officer motioned for Davis to follow him.

"Return when you have been released," ordered Lord Hastings.

"Very well," said Davis.

He left the cabin.

"Now," said Lord Hastings to Von Rosten, "I would be glad if you could do a further favor for me?"

"Consider it granted if it is within my power," said the young German.

"Thanks," said Lord Hastings. "I should like to borrow half a dozen of your crew. As you know, I am short handed, and I have work to do."

The German hesitated, but only for a moment.

"Very well, sir," he returned. "I shall be glad to let you have them. Would you also wish me to take care of your British prisoners?"

"Oh, no," replied Lord Hastings with a gesture. "They are hard workers, with a little urging," and he smiled. "They may come in very handily."

"As you please," replied the German.

A third time he summoned his first officer.

"Pick twelve men of the crew and have them ready to go aboard the U-16 with Captain Bernstorff here," he commanded.

The officer saluted and withdrew.

"Now, is there anything further I can do for you?" asked Von Rosten.

"Nothing, thank you," replied Lord Hastings, "and, with your permission, as soon as Davis is freed of his shackles and the men are ready, I shall return to my own vessel. I have work to do."

The young German bowed.

Half an hour later Lord Hastings, Jack and Frank again trod the deck of the U-16. Davis and a crew of twelve German sailors also were aboard.

"And now," said Lord Hastings, "having dispensed with the formalities, it is time to get busy."

CHAPTER XV.

PLOTTING.

"Now," said Lord Hastings, "as soon as we have lost sight of our new friend, Von Rosten, we shall take a little trip to Ostend anyhow."

"What for, sir?" asked Frank.

"Oh, just to look about a little," was the reply. "We may be able to pick up a little useful information."

"And why didn't you tell Von Rosten you were bound there, sir?" Jack wanted to know.

"Well, for one reason, because I wanted to borrow a part of his crew," said Lord Hastings. "Had he known we were headed for Ostend he would have thought it strange that we didn't wait until we got there to get more men. Besides, I wouldn't want to try and get men there. It might prove embarrassing."

"Well, sir," remarked Frank, "that was quite a little story you concocted for his benefit."

"I flatter myself it wasn't so awfully bad," smiled Lord Hastings. "Of course, I might have done better if I had been given more time."

"It was pretty good for a quick one," Jack admitted. "But, what are we going to do with Davis, sir?"

"Turn him over to the British authorities at the first opportunity. He is deserving of whatever punishment he shall receive. But in the meantime we must not let him suspect our true identity for he may be of use to us."

The lads nodded.

"Now," said Lord Hastings, "we may as well put about and run for Ostend."

Frank gave the command to Edwards, at the wheel, and the U-16 came about and headed east. Frank and Jack went below to their quarters, leaving Lord Hastings alone on the bridge.

"There is no use talking," said the latter. "It seems rather peculiar to be sailing under the German flag."

"And that's no joke," Jack agreed. "I hope we will not have to do it long."

It was late in the evening when the submarine approached Ostend, where it was known that the Germans had established a submarine base. The U-16 went along slowly, for Lord Hastings was not certain of his bearings.

Suddenly there came a hail across the water and a light flashed upon the U-16. In response to a command Lord Hastings brought the vessel to a halt.

"Who are you?" came the challenge in the darkness.

"U-16, Captain Tarlenhein," Lord Hastings shouted back.

"Good," was the reply. "We wondered what had happened to you. Everything all right?"

"All right."

"Ready to join us in another desperate mission?"

"Yes. Ready any time."

"Good. Remain where you are. We start within the hour. Your instructions will be sent to you."

Lord Hastings signified that he understood and the light on the other vessel was flashed off, leaving the U-16 in darkness again.

"Now what do you suppose is up, sir?" asked Frank eagerly.

"You have just as much idea as I have," declared Lord Hastings. "However, we shall probably know in good time."

And he was right.

Half an hour later a small boat approached the side of the U-16. In response to a signal from Lord Hastings, who had perceived his approach, a subordinate officer clambered aboard.

"Captain Tarlenhein?" he inquired.

Lord Hastings kept his face half turned in the darkness.

"Yes," he replied in a husky voice.

The officer drew a paper from his pocket and passed it to Lord Hastings.

"From Admiral Seibert, sir."

He brought his heels together, gave a quick salute, turned on his heel, and went back over the side.

Lord Hastings immediately hastened to his cabin and as hastily summoned Jack and Frank.

"Well," he said quietly, "here are our orders," and he laid the paper on the table. "Sit down."

The lads did so, and Lord Hastings, seating himself, picked up the document, broke the seal, and read aloud:

"Captain Tarlenhein,

"Commanding H.I.S. U-16:

"Proceed immediately, under command of Admiral Schuler, to Dover Bay, joining submarine flotilla there, to proceed to the Thames for attack British fleet. Flotilla to gather mile off Dover, midnight, Thursday.

(Signed) "SEIBERT."

"I should say that is plain enough," said Lord Hastings, looking up.

"Rather, sir," agreed Frank. "All we have to do is to be at a certain spot at a certain time."

"That's it. And the beauty of it is we do not go with any other vessel. I suppose Admiral Seibert deems it advisable for each vessel to make her way there separately, coming to the surface at the appointed time."

"And shall we be there, sir?" asked Frank.

"Rather," replied Lord Hastings dryly. "First, however, we shall have to find time to run even closer to Dover, take a trip ashore, and notify the Admiralty. Then perhaps we can arrange a little surprise for our friends the enemy."

"That's the way, sir," said Frank enthusiastically. "And I would suggest that the sooner we get under way the better. It may not be so easy to get ashore without being sent to the bottom by one of our own ships or forts."

"Very well," replied Lord Hastings. "You may give the word to proceed at eighteen knots, Mr. Templeton."

Jack gave the order, and the U-16 moved off in the night.

Having obtained Lord Hastings' permission, Frank and Jack decided to turn in. They made their way to the quarters they had chosen, and what was their surprise to find that Davis had appropriated it for his own convenience.

"I say," said Jack to Davis, who was sitting there in a comfortable chair, "you'll have to come out of here, you know."

"Will I?" said Davis. "What for?"

"Chiefly because we say so," replied Frank angrily. "This is our cabin."

"Yours?" repeated Davis, a rising inflection in his voice. "And who gave it to you, if you please?"

"We selected it," replied Frank, growing angrier at Davis' words.

"Well, I can't see that that makes it yours," returned Davis. "However, we won't argue about that. I'll just stay here and you go some place else."

"Not much you don't," declared Frank. "Either you'll skip out of here right now, or I shall have to throw you out."

"I don't believe you will do a whole lot of throwing," smiled Davis. "Anyhow, I'll take a chance by staying."

He settled himself more comfortably in his chair and picked up a book.

Frank's eyes flashed angrily, but Jack laid a soothing hand on his friend's shoulder.

"Let him alone," he commanded.

"What for?" demanded Frank. "Think I am going to let a man like him run me out of my own quarters? Not much."

"But we can seek other quarters," said Jack, who was always peaceable until aroused. "What's the use of getting in trouble?"

"It won't be much trouble," said Frank. "I'll just throw him out."

Jack smiled.

"He might fool you," he said quietly. "To me, he looks as though he would be hard for you to handle."

"I suppose you think you could do it all right?" said Frank.

"Well, I suppose I could if I started out to," declared Jack. "But I don't intend to make a fool of myself."

This answer only served to enrage Frank the more and he advanced upon Davis threateningly.

"Are you going to get out of here?" he demanded angrily.

Davis looked at him lazily.

"Well, no," he said at last; "I'm not."

Frank sprang upon him without another word and, seizing him by both shoulders, bore him over to the floor, falling on top of him. Then the lad quickly raised himself to his feet, and when Davis got up a moment later Frank grabbed him by the back of the neck with his right hand and the trousers with his left and hustled him to the door.

In vain did Davis seek to free himself from this hold. Although he was undoubtedly stronger and more than a match for Frank, the lad had him at a disadvantage; and he could do nothing to help himself as the boy hustled him through the door of the cabin.

There Frank gave Davis a last vigorous shove and he went spinning down the little hallway.

"There," said Frank, "perhaps that will teach you to stay where you belong."

He stepped back in the cabin, closed and locked the door. Then he turned to Jack.

"He's gone," he said quietly.

"I see he has," replied Jack, smiling. "Now, let's get to bed."

But Davis, routed though he had been, still had a few remarks to make. He tried the knob of the door, and, finding it locked, raised his voice.

"Hey! Let me in there," he demanded.

"You're out; stay out!" said Frank.

"You come out here and I'll punch your face," said Davis.

"Oh, I guess not," replied Frank, feeling quite well pleased with himself.

"You little Dutchman!" exclaimed Davis.

"Go hunt a hole and go to bed," said Frank.

There was no danger of his getting angry, for he was too amused. "If you don't," he continued, "I'll come out there and chuck you overboard."

"Oh, you will, will you? Well, come out here and I'll show you."

"Some other time," said Frank cheerfully.

"Right now I am going to turn in. Pleasant dreams to you, Mr. Davis."

Davis was very angry now. Outside the door he stamped his feet one after the other and rattled the knob vigorously.

"Let me in there, or I'll break this door down," he said fiercely.

During all this conversation Jack had shed his shoes and outer garments and was about ready for bed. He now decided that the affair had gone far enough and stepping forward called through the closed door:

"That's enough, Davis. Keep quiet, or I'll take a hand in this myself. If I do, you'll be sorry. Get away from that door!"

And Davis subsided.

CHAPTER XVI.

AN ENEMY SUNK.

"Steamship off the port bow, sir!"

Frank gave the hail from the bridge. A moment later Lord Hastings emerged from the little conning tower. For several moments he gazed searchingly across the water through his glass.

"Britisher," he said finally. "Guess we had better submerge."

"Why, sir?" demanded Frank. "Surely we have nothing to fear from one of our own vessels."

"You seem to forget about this German flag we carry," said Lord Hastings; "also, that, so far as we know, there are no British submarines in these waters."

"That's so, sir. I had forgotten just who we are supposed to be."

"We'll go below," said Lord Hastings.

He moved toward the conning tower, but even as he would have descended below, Frank gave a sudden cry.

"Submarine approaching the steamer, sir."

Lord Hastings immediately turned his gaze toward the vessel again. Frank had spoken truly. Halfway between the steamship and the U-16 a second submarine had suddenly appeared. Even from where he stood, Lord Hastings could see that the steamer had been ordered to halt.

"By Jove!" he exclaimed. "They're going to sink her!"

Jack came on deck just in time to hear his commander's last words, and he took in the situation at a glance.

"And we can't remain here idly and let a thing like that happen," he declared. "Come, sir, we'll go below and we'll have a shot at our German friend there."

"You forget," said Lord Hastings dryly, "that for the moment we are one of our friend, the enemy."

"But we can't let them sink the liner, sir!" exclaimed Frank in dismay. "We can creep up on them and launch a torpedo, sir."

"And be discovered ourselves?" remarked Lord Hastings. "Remember, we are playing for bigger game than a single German submarine."

"But no one will know the difference, sir. See, there are no other submarines near. If we sink this fellow, who is to know how it was done?"

"Your reasoning is all right," replied his commander, "but another submarine is likely to appear at just the wrong moment, and then what?"

"But surely, sir, you do not intend to remain here and let all the people aboard the liner drown?"

"The chances are that they won't drown," returned Lord Hastings. "Even now you can see that the vessel has halted. The German will give passengers and crew time to take to the boats."

"But they may not, sir."

"Well, we'll get as close as possible," said Lord Hastings, "and if the German threatens to sink the vessel before all are safely off, I'll give my permission to sink her. But I do not wish to risk discovery unless it is absolutely necessary."

With this the lads were forced to be satisfied.

The U-16 had now come within perhaps a hundred and fifty yards of the other submarine, which in turn was possibly another hundred yards from the big liner. The voice of the commander of the German under-water craft carried plainly to the U-16.

"Five minutes more," he called to the commander of the liner. "I can wait no longer. If all have not left the ship by that time, I shall sink you anyhow."

Instantly all became confusion aboard the steamship. Men, women and children ran shrieking up and down the deck; seeking a place of safety.

A boat was lowered over the side loaded with passengers. Hardly had it struck the water when perhaps a dozen men and women flung themselves over the side of the vessel into the boat. The little craft, already overloaded, could stand no more. It tilted gradually to one side and then suddenly turned over.

The occupants were thrown into the water and disappeared beneath it. Soon heads bobbed up here and there and pitiful cries were borne across the water to the U-16.

A second small boat, launched in haste, met the same fate, as did a third.

The panic aboard the liner became more acute. Hoarse commands of men and shrill cries of women and children rang out over the sea, while at the same moment the commander of the German submarine called out:

"Hurry now! Five minutes more!"

Lord Hastings took his decision instantly.

"Below," he said quietly as he led the way. Frank and Jack followed.

"Submerge, Mr. Templeton," came Lord Hastings' sharp command.

Jack gave the order. The conning tower was hermetically closed instantly and Lord Hastings took his place at the periscope. When the U-16 had submerged until the periscope barely protruded above the water's edge, Lord Hastings ordered:

"Hold her there!"

Orders came thick and fast now. Gradually the U-16 swerved a bit, to better bring her torpedo tubes to bear. Lord Hastings gave a hurried order to Jack, who stood at his elbow.

"Let no one come near me here," he said. "It would not do to have Davis or one of the crew see what we are about to do."

"No one shall pass me, sir," was Jack's quiet response.

"Good. Signal No. 2 torpedo."

Immediately upon going below Frank had ordered the men to their posts, where they now stood, eagerly expectant—the German members of the crew because they believed a British ship was to be torpedoed, and the Englishmen because they knew a German craft of some kind had been encountered.

The electric signal board aboard the submarine now flashed red:

"No. 2 torpedo!"

The man on duty there, who chanced to be a German, stood tense and expectant.

"How does she go above, sir?" asked Jack.

"Still a panic on the liner," returned Lord Hastings. "Several boats have been lowered safely, however, and are picking up those in the water. If the German will withhold his fire for ten minutes, all will be saved."

"Does he seem to be ready to fire, sir?"

"He seems to be holding off and I hope he does. However, I'm ready, and we'll beat him to it."

"I——" began Jack, and whirled about suddenly. He had caught the sound of footsteps behind him.

The lad looked into the face of Davis.

"Stand back there!" he commanded sharply.

"Why? What's the matter? What's going on?" demanded the latter.

"None of your business," replied Jack. "Back now, quick!"

"Look here——" began Davis.

"You heard me," said Jack slowly and very quietly. "Now obey and be quick about it."

"By whose command?" inquired Davis with a leer.

"By mine," returned Jack, restraining his temper with difficulty.

"I don't recognize your authority," declared Davis, and took another step forward.

Lord Hastings had been peering intently into the periscope and had paid no attention to what was going on behind him. He had given Jack his orders and he knew they would be carried out. However, now turning from the periscope to speak a word to the lad, he saw what was going on and he caught Jack's last words and Davis' reply.

"Then perhaps you will recognize mine," he said. "Stand back, sir!"

Without awaiting a reply he again turned to the periscope. For a moment Davis hesitated and seemed about to protest, but Jack gave him time for no further words.

The lad stretched out a long arm quietly, seized Davis by the elbow, drew him toward him a pace, and then hurled him violently backward. Davis went tumbling head over heels. Jack wasted no further thought on him, and turned to Lord Hastings.

Davis, very angry, pulled himself slowly to his feet and glared at Jack evilly. Suddenly he put his hand to his belt, whipped out his revolver, and levelled it straight at Jack.

But before his finger could press the trigger his wrist was seized in a strong grasp from behind and the weapon was twisted from his hand. Whirling angrily Davis looked into the face of Frank, who was smiling quietly.

"What's the meaning of this?" demanded the latter.

Davis face turned dark with rage.

"I'll show you," he cried, and struck a vicious blow at the lad.

But Frank had been prepared for some such move and stepped back quickly.

Davis missed.

Frank realized that this was neither time nor place to settle his grievance with Davis, so he took the simplest way out. His hand flashed to his belt and his revolver came to a level.

"That's enough," he said sharply. "One step forward and I'll shoot, so surely as my name is Frank Chadwick."

There was no mistaking the menace in the lad's tones, and growling to himself, Davis dropped his hands. Then, still muttering and keeping at some distance, he slunk away, hurling over his shoulder:

"I'll get you for this yet. Remember that."

Frank did not take the trouble to reply, but instead approached Jack and Lord Hastings.

"How are things, sir?" he asked.

"At a standstill," replied Lord Hastings. "The German is withholding his fire, but there are still people on the liner. If he will restrain his impatience for a few minutes everything will be all right."

"Perhaps he will, sir," said Jack hopefully.

"I trust so. It will be better for all concerned. Everything ready, Frank?"

"All ready, sir. You're sure No. 2 torpedo has the range?"

"Perfectly. It will reach the enemy's bridge at its present angle."

"Could I have a look, sir?" asked Frank.

For a brief moment Lord Hastings hesitated, then stepped aside and motioned Frank to his place at the periscope.

"Give the command to fire if anything happens," instructed Lord Hastings.

Frank nodded, and placed his hand on the signal button, at the same time peering into the periscope.

Above everything was perfectly plain. The lad could see that the captain of the liner and some passengers still remained aboard; and, a short distance away, he saw the German submarine, with her commander standing upon the bridge, watch in hand.

Suddenly the German's watch closed with a snap. Frank drew a sharp breath, for he realized what was coming. Slowly the German officer's hand moved upward. Frank divined that he was about to give the signal to fire a torpedo at the defenseless vessel.

Frank's heart leaped into his mouth; and he pressed the little button beneath his finger. And once again the signal board on the U-16 glowed red:

"Fire!"

CHAPTER XVII.

AN ARGUMENT SETTLED—TEMPORARILY.

There came a sharp, metallic click; and after it the silence of death aboard the U-16 for a brief second while Lord Hastings took Frank's place.

Then the German sailor who had launched the torpedo cried out:

"Did we hit her, sir?"

Lord Hastings took his eye from the periscope long enough to answer: "Squarely on the bridge, my man."

The sailor gave a guttural exclamation of joy, in which his countrymen joined. The three Englishmen had the presence of mind to say nothing. Then one of the Germans turned to Edwards, who stood by him at that moment.

"There goes one of your vessels," he said happily.

"Where many of yours will go before long," returned Edwards, turning away to hide a grin.

"Then we hit her, sir?" questioned Frank eagerly.

"We did," returned Lord Hastings.

"Shall we go to the surface again?" Jack asked.

"Hardly," returned Lord Hastings dryly. "The men naturally would want to go on deck to have a look at their work, and when they saw a British steamship floating safely they would probably do some thinking. No; we'll submerge still deeper and get away from here."

"And the people aboard the liner, sir?" asked Frank.

"Will have to shift for themselves," was the reply. "However, they are in no danger now."

"Very well, sir."

"You may submerge to ten fathoms, Mr. Templeton," said Lord Hastings.

Jack gave the order, and a moment later the tanks of the U-16 began to take in more water. When at the proper depth, Lord Hastings ordered full speed ahead.

"Where now, sir?" asked Jack.

"To where we can do the most good," was his commander's reply. "To Dover, where I shall make an attempt to acquaint the British authorities with what we have learned."

"And where we'll set a neat little trap for the enemy, sir," said Frank eagerly.

"We'll try," returned Lord Hastings grimly.

One of the Germans was now called to take the wheel, and, leaving Lord Hastings in the latter's cabin, Jack and Frank made their way aft. Here, as they passed the compartment in which the crew bunked, they heard a commotion.

The two lads entered quickly. There, in the middle of the floor, surrounded by half a dozen of the German sailors, stood Davis, and confronting him was the British sailor, O'Brien. The latter was speaking.

"Yes, I called you a contemptible traitor," he said, thrusting his face forward and speaking in German. "What are you going to do about it?"

"I'll show you," replied Davis.

He raised an arm suddenly, and, taking O'Brien off his guard, sent him to the floor with a blow to the point of the chin. The man lay still.

Frank's blood boiled.

"Guess I'll take a hand in this myself," he said through his teeth. "I've been wanting to get at him for some time now."

In vain Jack sought to stay his chum. The latter shook off the detaining hand and sprang forward. Before Davis noticed his presence the lad was upon him.

There was a resounding smack as Frank struck Davis lightly across the face with his open palm.

"You big coward," he said, "to taunt a prisoner. I'll teach you a little lesson. Take off your coat."

For a moment Davis shrank back before the boy; but seeing the eager faces about him and realizing that the others expected something from him he jerked off his coat and faced the lad.

"You'll wish you had kept out of my path," he sneered.

It was plain to be seen that sentiment was about evenly divided among the German crew. The men knew neither of the combatants were German, and while they knew that Davis was a traitor to his country, they had a pretty good idea that Jack and Frank were too. For some reason, however, none had the slightest doubt that Lord Hastings was a German.

Now Jack stepped forward, and, speaking in German, said:

"Men, as long as these fellows have got to fight, it may as well be done right, eh?"

There was a general murmur of approval from the crew.

"All right," said Jack. "Now, we won't have any rules, except that this is to be a straight fight. No kicking, biting nor gouging. Nothing but fists go." He looked Davis squarely in the eye. "Do I make myself clear?" he asked.

"Yes," replied Davis sullenly.

"Good. Then when I say 'go' you can tackle each other until I cry stop, which shall be at the end of fifteen minutes, if you are both on your feet. And then you'll stop if I have to take you both in hand. Stand back, men."

The Germans crowded back to the edge of the little room to give the combatants free play. To most of them this was something new.

Most had seen many fights and duels, but it is doubtful if any had ever witnessed a stand-up fight with bare fists. They leaned forward expectantly.

Frank and Davis had both rolled up their sleeves and now awaited the word, Davis sullen and glowering, and Frank cool and collected, apparently, though to Jack's keen eye the lad was plainly very angry. Jack was not without some misgivings as to the outcome of the encounter, for Davis was much the larger of the two.

Also he was apparently much stronger than his adversary, and from his position Jack knew that he must know something of the pugilistic art. To Jack, an exceptionally skillful boxer himself, it looked as though Frank had tackled more than he could finish.

"If Davis were only a German now," he muttered to himself. "But he's English, and, although he's a traitor, he'll probably give Frank a trimming."

"All ready," said Jack, watch in hand. "G——"

At this moment there was an interruption from the doorway.

"What's the meaning of this?" demanded a stern voice.

All turned quickly. Lord Hastings stood in the doorway.

"I say, what's the meaning of this?" he demanded.

"Just a little personal affair, sir," replied Frank, stepping forward. "Davis here and I are going to settle a difference."

"Hm-m-m," muttered Lord Hastings, sizing the two up critically. "And you think you can thrash him, eh?"

"I think so, sir."

"Well, I don't," was the reply. "I have a notion to forbid it."

"Don't, sir," pleaded Frank. "It will have to come some time, and the sooner the better."

Lord Hastings was plainly undecided. But at last he threw open his arms in a gesture of permission.

"Go ahead, then," he said. "I'll stay and see fair play."

Watch in hand, Jack raised an arm. He was silent a moment. Then,

"Go!" he said, "and remember, fight fair!"

The two combatants had sprung forward before the words were out of Jack's mouth, and the latter was obliged to skip nimbly aside to get out of their way.

Davis rushed forward to meet Frank, who advanced more slowly, though with confidence written large on his features. Jack, perceiving this, shook his head sadly.

Frank evaded Davis' first terrific blow, that must have laid him flat had it landed. Side-stepping neatly, he struck Davis a light and glancing blow over the right ear. There was little force behind it and Davis did not even wince. He whirled and rushed again.

Again Frank side-stepped and planted a light blow to Davis' head, following it up quickly with a heavier blow to the forehead. Davis shook his head, and, raising his guard, stood still. Evidently he had decided to try no more rushing tactics.

Frank, nothing loath to take the offensive, advanced confidently. He feinted with his left and drove hard with his right. He knew that he gauged the distance carefully and he was unable to account for the fact that the blow failed to land. A moment later he staggered back a trifle from a blow upon the side of the cheek. Davis had outgeneraled him there.

There was not much force to the blow and Frank smiled. Now Davis advanced, and, feinting rapidly with both hands, placed his right against Frank's mouth. But the lad had perceived the blow coming and stepped quickly backward, breaking the force of it, and was not hurt. Before Davis could cover, the lad placed a hard right and left to Davis' nose, bringing blood. Davis gave ground.

Frank followed up this advantage quickly and followed his man around the room, striking out whenever opportunity offered. Plainly Davis was becoming rattled. He continued to retreat. Now Frank backed him into a corner and drove a hard uppercut to the chin. Davis' head jerked backward and struck the hard wood of the wall. Frank stepped back and allowed Davis to come out of the corner.

Davis, it could be plainly seen, was furiously angry; but he held himself in check, apparently realizing that victory depended upon coolness and caution.

Frank advanced swiftly, swung and missed by a fraction of an inch, as Davis jerked his head sharply to one side. Before the lad could recover, Davis struck out viciously and landed flush on Frank's jaw. The lad staggered back, but before Davis could follow up his advantage, Frank covered and held his opponent off. The blow had been the hardest of the fight so far.

Davis, with more confidence since this blow, stepped forward aggressively, feinted quickly two or three times, and sent a hard right to Frank's sore jaw. Again Frank covered up and gave ground. Believing that he had the lad at his mercy, Davis advanced quickly and swung hard with his left.

With dazzling rapidity, Frank stepped inside and, catching the swing with his left arm, planted his right fist squarely upon Davis' nose. Davis uttered a cry of pain and leaped back. Frank followed, pressing him closely.

Davis seemed content to remain on the defensive now, and for the space of perhaps a minute warded off all the lad's blows with a really remarkable defense. Even Jack was forced to give him his due.

"He can box," he muttered, "but I doubt if he can keep his head."

But the end of the battle came now with sudden and unexpected swiftness. Frank, seeking to put an end to the fight, stepped forward, feinted with his left, and drove his right straight for Davis' chin, swinging from the floor.

Davis jerked his head back sharply, and the lad missed. Before he could recover Davis had swung hard with both hands and both blows went home, one catching Frank in the abdomen, doubling him up, and the other straightening him again as it landed squarely on his chin.

Frank dropped to the floor and lay still.

CHAPTER XVIII.

MISTAKEN FOR AN ENEMY.

Davis had won—fairly and cleanly—there was no doubt about that.

But Jack and Lord Hastings wasted no time in considering the merits of the encounter. Each sprang forward and bent above the lad. Lord Hastings raised the boy's head to his knee.

"Water," he said to Jack.

The latter hastened to get it, and after a few drops had been sprinkled over his face, Frank opened his eyes. He glanced up curiously at Lord Hastings.

"What's the matter?" he asked. "What's happened?"

"Matter is," returned Jack quietly, "that you have just been convinced that you are not such a terrible fighter as you have been thinking."

"You mean he licked me?" demanded Frank, suddenly realizing just what had happened.

"He did," returned Jack dryly; "and he did a pretty good job of it."

"But I tell you I had him," cried Frank. "One more blow and—and——"

"The one more blow didn't land," replied his chum.

"But I tried——"

"Yes, you tried, all right. I saw you. You just missed him and then he landed on you—twice, and hard. That's why you're here."

"He couldn't do it again," said Frank feebly.

"Maybe not and maybe yes," said Jack. "However, you're not going to have another trial. You've been licked, and licked good and proper, and that's all there is to it. See if you can get up now. I'll take you to our own quarters."

Frank pulled himself to his feet, and, leaning on Jack, walked from the room.

Davis now had donned his coat and stood near as the two passed out. There was a sneering smile on his puffed face, and he spoke.

"Perhaps you fellows will pay a little more attention to me when I say something after this," he muttered.

Jack whirled on him sharply.

"See here," he said quietly, "if you make any trouble in the future I'll take you in hand myself. You'll find that the result will be somewhat different."

"So?" sneered Davis, feeling not a little proud of himself. "You are at liberty to try at any time. Right now, eh?"

He made as if to discard his coat. Flushed with victory, he manifested no doubt that he could handle Jack as well as Frank.

In spite of himself, Jack was forced to smile.

"We won't fight now," he said quietly. "You're not in condition in the first place. But when you have been fixed up, I just want to tell you not to trifle with me."

"Threats, eh?"

"Call them what you please. I don't want to have to spank you, but I may have to. Don't bother me, that's all."

He helped Frank from the room without another word. Lord Hastings, about to leave the room, stopped for a word with Davis.

"Just a word of advice," he said. "As you know, we are on a perilous duty. Any more trouble and I'll have you ironed if necessary. You're in no position to make a nuisance of yourself."

Davis made no reply. He recognized Lord Hastings' authority to do as he said and he was smart enough to say nothing. Lord Hastings left Davis with the sailors.

An hour after leaving the spot where the U-16 had so recently sent a German submarine to the bottom, Lord Hastings again gave the command to come to the surface; and the vessel proceeded then upon the top of the water.

Frank and Jack, tired out, had retired for a brief rest before their services would again be required; but had they been in Davis' cabin they would have overheard a strange conversation.

Davis and three of the German sailors were engaged in a deep and apparently serious discussion. They talked in subdued tones and cast occasional furtive glances at the door. Occasionally the three nodded their heads affirmatively as Davis talked, each occasionally volunteering a few words himself.

"Then you are with me?" asked Davis at length.

The men nodded.

"Good. But we shall have to bide our time. A false step and it would be the end of all of us. This Commander Bernstorff, I should say, is a bad man to fool with. But once we can get him in our power and silence the others, we can make something of ourselves."

"Yah!" muttered one of the sailors. "What is this war to us anyhow? You are English and we are German; but what of it? Why should we take orders from such men as Herr Commander Bernstorff and others of his kind?"

"Why, indeed?" echoed another.

"You are right," said Davis. "Now, when we take possession of this vessel we will be our own masters. No one to tell us what to do. We won't have to risk our lives for some one else's gain. And what booty we can get shall be evenly divided among us. There is rich prey upon the sea."

"But first," said one of the sailors, "to come into possession of this vessel, we shall have to dispose of Commander Bernstorff, his lieutenants, and others of the crew."

"How," exclaimed one of the others suddenly, "how if some of the others would join us? I have no doubt they would if approached in the right way."

"We don't want too many," protested the third. "The fewer of us, the fewer to share in the spoils."

"True enough," said Davis, "but we must have men enough for a crew. I, of course, shall command. You three will be my officers. We must have a crew."

"How about the English sailors?" asked one of the Germans. "They must be dissatisfied. Here they are prisoners and will be kept under guard until the end of the war. Certainly they should be willing to join us. It will mean freedom and a share in the rich spoils."

"With which to retire when the war is over," put in another. "Why, we can go to America and live at ease for years to come."

"Which is my plan exactly," declared Davis. "Yes, we must have a crew. Hans, do you think you could approach these prisoners?"

"Leave that to me, sir," replied Hans with an evil wink. "I think I can convince them, sir."

"Good; but in the meantime, do not talk this among yourselves. I believe we had better wait until after the end of the expedition we are now on. Vigilance, probably, will relax then. In the meantime, we must try and show ourselves to be perfectly loyal to the Kaiser."

"Very well, sir."

"All right then," said Davis. "You fellows clear out now. I want to get a little sleep."

Silently the three conspirators made their way from the traitor's cabin. No one saw them go and the success of the plot seemed assured as the U-16 continued on her journey, Lord Hastings, Frank, Jack and the other British aboard unaware and unsuspecting.

Shortly after dusk of the night upon which the German under-sea fleet expected to spring its coup, the U-16 lay upon the calm surface of the water still some distance from the point set for the gathering of the submarine flotilla at the midnight hour, and likewise a considerable distance from Dover.

Explaining his reason for stopping here, Lord Hastings said: "There may be British patrol boats about—probably are. I want you boys to remain in charge here, while I take a boat and try to reach the British authorities."

"One of us had better go along, sir," declared Frank.

Lord Hastings considered this a minute.

"I don't know but you are right," he finally said. "Frank shall go. Jack will take command in my absence."

He addressed the latter. "Arm Edwards and our other men," he continued, "though do it unknown to the Germans. I don't altogether trust this Davis. Of course he is in the pay of the Germans; but once a traitor always a traitor. Watch him closely."

"I'll watch him," said Jack quietly.

"Very well. Frank and I shall leave at once."

Lord Hastings ordered a small boat over the side, the two jumped into it and rowed rapidly away, leaving Jack to pass the word among the crew that Commander Bernstorff had gone on a little scouting expedition.

For half an hour Lord Hastings and Frank rowed along without incident until they could see a few dull lights in the distant town of Dover.

"Seems to me there is a terrible lack of vigilance hereabouts," declared Frank.

"It does look that way," Lord Hastings admitted. "However——"

There came a sudden interruption—the sound of a shot, and a bullet whistled overhead.

"Not such a terrible lack of vigilance, either," remarked Lord Hastings. "I wonder where that shot came from?"

He gazed about but could see nothing in the darkness. Came a second shot from behind him, and turning, the two saw a little motorboat that had crept up behind them unnoticed.

"We surrender!" called Lord Hastings, fearing to take a chance that the next shot would miss.

The motorboat came toward them quickly.

"Who are you?" demanded a figure standing in the bow, and at this distance Lord Hastings could dimly make out that the man wore a British uniform.

"Friends," was the reply.

The British officer peered at them sharply, then noticed their German uniforms.

"Friends, eh," he said; "in those uniforms. Not likely. Climb into my boat."

Lord Hastings and Frank obeyed without a word, and at a command from the British officer the motorboat put about and headed shoreward.

"Where are you taking us?" asked Lord Hastings quietly.

"None of your business," was the sharp response.

"So?" said Lord Hastings quietly. "I would advise you to speak more respectfully. I would not like to report you. I asked you a civil question and I would appreciate a civil answer."

"Well, I'll tell you, seeing that you are so anxious," replied the officer. "I am taking you to Admiral Fischer, at Dover, who, most likely, will know better how to attend to your case than I do."

"Most likely," repeated Lord Hastings. "And how long before we may expect to see the admiral?"

"About half an hour."

"Good!" And Lord Hastings whispered to Frank: "Plenty of time. Fortunately I am well acquainted with Admiral Fischer."

CHAPTER XIX.

THE TRAP IS SET.

"Hastings!"

The exclamation was wrung from the lips of the astonished Admiral Fischer, in command of the naval forces operating about Dover.

"Right you are, Fischer," was Lord Hastings' smiling rejoinder, "though how you recognized me in all this German toggery is more than I can explain."

The admiral advanced and wrung Lord Hastings' hand.

"And why this German uniform?" he asked. "And who is this young man with you?"

"I'll answer the last question first," smiled Lord Hastings, "by presenting to your excellency, my second officer, Mr. Frank Chadwick."

Admiral Fischer acknowledged the introduction.

"Now for the answer to my other question," he said.

In a few brief words Lord Hastings explained. As he progressed with his recital Admiral Fischer became more and more astonished. And when Lord Hastings had concluded, the admiral burst out:

"And you mean to tell me the Germans have the temerity to attempt a raid in the very mouth of the Thames?"

Lord Hastings nodded.

"They certainly have," he said quietly, and he produced the order he had received from the German admiral.

Admiral Fischer scanned it closely.

"It's authentic enough," he said finally, "I know his signature well. And this raid is to take place at midnight, eh?"

"Well, no. We are to gather at midnight. How long it will take to reach the mouth of the Thames you can figure yourself."

"I can," declared the admiral. "And I can also figure that if these submarines dare enter the Thames they will never get out."

"But you must figure better than that, Admiral. You must figure so they will be unable to do any damage. That's even better than figuring that they cannot escape after the damage is done."

"So it is," returned the admiral. "Have you a plan?"

"Why, yes! You must immediately order all warships and other craft now at the mouth of the Thames, further up river. Order a swift torpedo boat flotilla down the river—as many as are available—and have half a dozen torpedo boats—equipped with nets—to take their places behind the motorboat fleet."

"And then?"

"Well, the motorboats will attack the submarines as soon as they appear. A few of them undoubtedly will be sunk. Then let the rest retire. The submarines, submerged by this time, will travel forward a bit. At this point have the torpedo boats, with nets stretched, proceed down each side of the river. Of course, the torpedo boats must advance at the moment the motorboats flee."

"But I should think the Germans are too wary to be caught in a trap like that."

"They won't be, because they expect the raid to be too unexpected for such details to have been arranged. Only one stipulation. Instruct all your officers under no circumstances to fire at the first submersible to move up the river."

"And why?" demanded the admiral.

"Chiefly," smiled Lord Hastings, "because I don't want to go to the bottom."

"Oh, I see! You mean to lead the German advance."

"Exactly, and for two reasons. First, because I wish to reach a place of safety at the earliest possible moment, and second, because if the Germans see one craft advance, apparently unafraid, the others will not hesitate to follow."

"But perhaps it will be impossible for you to lead the way."

"You just leave that to me, Fischer. I shall be in the first submarine. The only question that remains is whether you have time to lay your plans."

"Plenty," was the reply. "I'll begin now."

He pressed a button on his desk and an orderly entered. At a command he left the room again, only to summon other officers. Admiral Fischer scribbled rapidly, passing paper after paper to different officers. At the end of another half hour, he turned to Lord Hastings.

"All ready," he said quietly.

"You have lost no time," replied Lord Hastings with a smile. He glanced at his watch. "Almost ten," he said. "Come, Frank, we shall have to hurry."

"Look here, Hastings," said Admiral Fischer, "don't you think you are taking unnecessary risks? What's the use of going back? Why not stay here?"

"Impossible, Fischer," returned Lord Hastings. "In the first place, some of my men are there and I must return to them. Then again, I want to be in the fun."

The admiral shrugged his shoulders.

"I know you too well to insist," he said. "So be it. But one thing; remember that you must be in the first submarine."

"I'll be there," said Lord Hastings.

Admiral Fischer summoned the officer who had conducted the two to him and instructed him to return them to where he had picked them up. The officer looked surprised, but he said nothing. Lord Hastings shook hands with Admiral Fischer and he and Frank followed the officer from the room.

Quickly they made their way back to the motorboat, were hurried out over to the dark water, and finally were given their own small boat again, in which they headed for the U-16.

"Think you can find her, sir?" asked Frank.

"No trouble at all," was the reply.

And there was no trouble.

By eleven o'clock they were safely back aboard and Jack received them anxiously.

"What luck, sir?" he asked.

"Excellent," replied Lord Hastings. "How did everything go in my absence?"

"All quiet, sir."

"No trouble with Davis?"

"No, sir. I haven't even seen him."

"Very well. Now you may give the order to submerge and we'll make for the rendezvous."

Jack obeyed.

It was just exactly three minutes to twelve when Lord Hastings, having taken his bearings and found he was in the designated spot, gave the command to come to the surface.

Slowly the U-16 arose from the deep, and immediately she rested upon the surface, Jack and Frank followed Lord Hastings to the bridge.

The night was perfectly dark and at first they were unable to make out an object upon the silent water. But suddenly, to the left, there was a single brief flash of light; a second to the right; one forward and one astern; then other arrivals from the deep flashed a signal of their safe arrival. Producing his small pocket flashlight, Lord Hastings did the same.

"Seven besides ourselves," he muttered to himself.

Slowly now the submarines drew closer together until presently a voice from the bridge of one could be heard by all as Admiral Schuler addressed his captains.

"We shall submerge until our periscopes alone show," he gave his orders. "Then we shall proceed at full speed for the mouth of the Thames."

"But mines?" protested a voice.

"The mines have been swept clear," was the reply. "A flotilla of mine sweepers have been busy since dark. Now, heed these orders: We shall keep as close together as possible. Reaching the Thames, one submarine must lead the way. I shall call for a volunteer."

"Here, sir," Lord Hastings spoke up before the other commanders had a chance.

The others also volunteered, but Admiral Schuler awarded the honor to the U-16.

"You spoke first," he explained. Then he continued: "Unfortunately, we have been unable to learn the exact positions of the various British war vessels in the Thames, but we do know that there are many stationed there—just how far up the river I cannot say. However, once there we shall not return until we have sunk them."

A subdued cheer ran across the water in the darkness.

"It is time to go," said Admiral Schuler. "I shall show the way to the Thames, when the U-16 will take the lead. To your posts and follow me closely."

He went below, and the other commanders did likewise. A moment later the purr of machinery became audible aboard each vessel. Each submerged until the tip of her periscope protruded above the water, and then they sped after the flagship into the darkness of the night.

Swiftly they went, for Admiral Schuler realized the value of haste. He wished to make the raid and be out to sea again before the break of day.

Aboard the eight units of the submarine flotilla there was joy unrestrained. The crews of each vessel had been taken into the confidence of their commanders by this time and the men aboard seven of the craft were eagerly awaiting the moment when they could strike a terrible blow at the British navy. In view of the successes that had already attended the efforts of the German submersibles, there was little doubt in the hearts of the men that the present venture would be accomplished.

Even the three British sailors aboard the U-16 were cheerful, for although they did not realize the exact import of their mission, they knew Lord Hastings well enough to realize that he was acting in this manner only because there was some big duty to perform. They were content to follow him blindly.

Perhaps the only four men with the fleet who did not really have their interests aroused were Davis and his three fellow conspirators. Their only hope was that the sooner they came through the venture successfully the sooner they might get to work on their own plans.

The submarine fleet sped silently through the waters, going as swift as the wind; and when it finally reached the broad mouth of the Thames, the key to London itself, it still lacked two hours of dawn. But it was time for quick work and Admiral Schuler was not the man to hesitate—had he been, he would not have held this important post.

The submarines came to the surface now, in accordance with previous instructions, and Admiral Schuler, by a signal with his light, instructed the U-16 to proceed ahead. The other vessels dropped back a little.

"Well," said Lord Hastings to Frank and Jack, who stood beside him on the bridge, "here goes. May good fortune attend us."

He gave Jack the command:

"Full speed ahead!"

CHAPTER XX.

THE TRAP IS SPRUNG.

As the three officers aboard the U-16 knew, British battleships and vessels of war of all descriptions had been stationed all along the Thames, many of them patrolling the very mouth of the river. But now, as Lord Hastings, Jack and Frank stood upon the bridge of the little submarine after it had entered the mouth of Thames, there was not a vessel of any kind to be seen in the darkness.

"Admiral Fischer's orders have been followed out, sir," said Jack in a low voice.

Lord Hastings nodded but made no reply.

Behind the U-16 the other German submarines followed closely, two abreast. Aboard each the men stood to their posts, awaiting the signal they expected at any minute. All the vessels moved along upon the surface. The officers, from their places upon the bridge, followed with their eyes the movements of the U-16, which displayed a small stern light to guide them on.

In case of danger Lord Hastings had been instructed to give immediate warning, that the vessels behind might have time to dive.

Perhaps a hundred yards away in the darkness Frank's keen eyes now made out the forms of many little craft approaching them silently and swiftly. He immediately called Lord Hastings' attention.

"The motorboats," replied the latter quietly. "Things are working out just right."

Behind the motorboat flotilla could be seen forms of larger and mightier ships of war—the torpedo boats which were advancing in the wake of the mosquito fleet to surround the enemy submarines and capture or sink them. They came along close to the shore on either side of the river and the U-16 continued up the river in the exact center.

"When we get by, they'll close in," said Lord Hastings.

But now one of the commanders with the motorboat flotilla could restrain his impatience no longer, and while still some distance from the enemy gave the command to fire.

A single big gun boomed in the darkness and a shell screamed over the U-16 toward the German submarines beyond.

"The fool!" exclaimed Lord Hastings angrily. "Why could he not wait? There is no reason for concealment longer."

Immediately he gave the signal agreed upon with the German admiral, the darkening of the tail light—the signal for the others to submerge—and the U-16 dashed forward faster than before—to reach a place of safety as quickly as possible and to get out of range of the British ships, which, a moment later, opened upon the enemy with every available gun.

Directly opposite the U-16 there was a terrible explosion, a blinding flash, illumining the night like day. A German submarine had launched a torpedo and it had gone home. The foremost British torpedo boat had been destroyed.

But the others rushed on.

The Germans had heeded Lord Hastings' signal to submerge and were doing their best to disappear beneath the water before the British could reach them, the while firing an occasional torpedo, in the hope that it would go true, for they were unable to find the range and were working on mere guesswork.

Before the first of the foe could submerge a shell from one of the little motorboats struck her squarely upon the bridge, killing the captain and other officers, and shattering the conning tower. The men below no longer had a means of guiding the vessel, which drifted toward her nearest neighbor and rammed her amidships. This blow, while not necessarily fatal, threw the latter out of her stride, and being unable to tell for the moment what was wrong, the German commander gave the order to cease submerging; and the vessel remained where she was until a shell from a British torpedo boat put an end to her.

The two enemy under-sea boats last in line had turned about with the first warning and were making full speed down river again. The rest had submerged before the British could come upon them and had sought to come about and make their way to safety beneath the water.

But the British vessels were too swift for them. With mine nets stretched clear across the river, now that the U-16 had passed to safety, the torpedo boats dashed ahead; and an hour later four more German submarines, caught in these powerful nets, were helpless. It only remained to drag them to the surface and make prisoners of the crews, which work was deferred until daylight.

Aboard the U-16 none knew what had occurred save the three upon the bridge—Lord Hastings, Frank and Jack. Below, all stood to their posts, awaiting they knew not what.

Jack descended.

"All right, men," he said, "you may turn in, if you wish. There'll be no fighting to-night."

There was an exclamation of disappointment from among the German sailors, who apparently had been banking on dealing a severe blow to the British. There were several questions, which Jack answered by saying:

"We haven't come upon the enemy yet, and will not to-day."

He returned to the bridge.

"I suppose," said Lord Hastings, "the best thing we can do now is to go ashore and report. Frank, you shall come with me. Jack will remain behind."

The lads nodded.

Half an hour later Jack was left aboard the U-16, while Lord Hastings and Frank were being rowed ashore.

Below, although Jack did not know it, trouble was brewing. Davis and his three fellow-conspirators were plotting again.

"And what did this man Edwards say?" demanded Davis of one of the Germans.

"He said he would let me know some time to-day," was the reply. "Also, that he felt sure the others would follow his lead—would do whatever he said. He agreed with me that this was no war of ours, and added that as long as kings and emperors were using us to do their will, there was no reason why we shouldn't confiscate the property of kings and emperors to gain a few advantages for ourselves."

"By Jove!" exclaimed Davis. "The fellow reasons well. He may prove the very man for us." And he added to himself: "It would be a good thing to have another Englishman with me, if he is of the right sort."

The conversation continued for some moments, and then Davis said:

"Say, one of you fellows, tell Edwards I want to see him now."

One of the men departed, and returned a moment later, followed by Edwards. Davis engaged him in conversation and the two talked in low tones for perhaps five minutes. Then Davis turned to the others.

"I can see no reason why we should wait longer," he said. "Bernstorff and one of his officers is ashore. There remains only one and the crew. We can dispose of the one officer easily enough, and as for the crew, I am of the opinion that most of them will join us."

"Then," said Edwards, "if you will wait here until I return I will get my other men."

"It would be better that way," agreed Davis. "There will be seven of us and that should be enough. Hurry."

Edwards withdrew. First he made his way to where O'Brien and McDonald were asleep, and, rousing them, bade them follow him; but instead of returning to Davis' quarters, he led the way rapidly to where Jack stood upon the bridge.

Edwards explained the situation in a few brief words and Jack was dumbfounded.

"And you say Davis is preparing to spring this coup to-night?" exclaimed Jack.

"Right now, sir," returned Edwards quietly. "That's why I brought O'Brien and McDonald here. We are all armed, sir."

"Oh, we are more than a match for Davis and his trio of conspirators," Jack agreed. "The only thing that troubles me is that the others of the crew may join him. We shall have to act quickly. Follow me."

He drew his revolver and led the way below. There he hurried straight to Davis' quarters and flung open the door. Then he stopped in surprise.

"No one here," he ejaculated.

He was right. Davis and the others had gone; and though Jack did not know it, they were at that moment aft haranguing the crew, who had gathered about them eagerly.

Every man aboard the ship was now armed, for Lord Hastings had decided it would be inadvisable to relieve them of their weapons—it would have aroused their suspicions—and they were receiving Davis' proposals with satisfaction. It seemed that they had long harbored such thoughts and all that had been needed to egg them on had been a leader. They seemed to have found one in Davis.

"Then you men are with me?" asked Davis, his face flushed with pleasure.

The answer was a cheer; and the cheer carried to Jack, who was still in Davis' quarters. It told the lad what had happened just as well as though he had been present and overheard the conversation.

"Quick men! Back to the bridge!" the lad exclaimed.

He dashed forward, but he was not quick enough.

As he left Davis' cabin the Germans appeared in the little passageway aft, Davis in advance. He saw Jack the same moment the latter saw him and both raised their revolvers and fired. But neither had paused to take careful aim and both bullets went wide of their mark.

Edwards and the two other British sailors now sprang into the little passageway and levelled their revolvers at the foe. For a brief moment the Germans hesitated, and in that moment the British poured in a volley. Two men fell, another groaned, and two cursed—while at a shouted command from Davis, the fire was returned.

The sailor McDonald flung wide his arms and toppled to the floor.

"Back, sir!" cried Edwards. "They are too many for us."

The three retreated along the passageway until they reached the ladder leading to the bridge.

"You first, sir!" said Edwards, at the same time firing down the passage.

Jack hung back.

"After you," he replied.

"Don't be a fool now," said Edwards. "Hurry, while I hold them off."

Again he fired at the crowd of German faces down the passage, as did O'Brien.

Jack hesitated no longer and climbed the ladder rapidly.

"You next, O'Brien," said Edwards.

O'Brien sprang to the ladder, but a bullet from a German revolver halted him halfway. He toppled over without a word. Edwards glanced at him quickly once, saw that he was beyond help, and sprang to the ladder himself.

A bullet struck him in the side but it did not stop him. Jack, at the top, lent the man a helping hand, and a moment later Edwards stood beside him on the deck.

"No time to waste, sir," said the sailor. "Over the side with you, quick!"

Jack flung himself into the river as Davis showed his face on deck.

CHAPTER XXI.

AT SEA AGAIN.

Edwards, also about to leap overboard at that moment, paused, raised his revolver, took careful aim at Davis and fired. Davis uttered a hoarse cry, dropped his own weapon, and crumpled up on the deck. Edwards smiled grimly, dropped his revolver and leaped lightly into the water.

He came up a moment later beside Jack, who was treading water while he awaited him.

"Which way, sir?" asked Edwards. "You know where we are. I don't."

"This," said Jack, "is the Thames. We'll have no trouble making shore. Follow me."

Edwards did so and a few moments later both stood dripping on land.

"Now where to, sir?" asked Edwards.

"We'll have to hunt up Lord Hastings. He's gone to make his report to the British authorities. By inquiring a bit we should have no trouble finding him."

The lad was right. A subordinate officer directed them to the quarters of General Hamilton, where Jack felt sure he would find his commander. At the door of the general's quarters an orderly halted them.

"Is Lord Hastings here?" demanded Jack.

"He is closeted with the general," was the reply.

"Well," said Jack, "you tell him his first officer is here and wants to see him immediately."

The orderly hesitated, but a second look at Jack and he did as commanded. A moment later Lord Hastings dashed out, closely followed by Frank.

"What's wrong?" he demanded.

"Nothing, only that we have been chased off the submarine," replied Jack quietly. "Davis headed a conspiracy to capture the vessel and I was unable to act quickly enough. Edwards and I escaped."

"And O'Brien and McDonald?" inquired Lord Hastings.

"Dead!"

"How about Davis and the others? Weren't you able to account for any of them?"

"A few, sir," returned Jack briefly, "but Davis——"

"I think I got Davis, sir," Edwards interrupted quietly. "I took a shot at him just before I went over the side. He went down."

"I'm glad to hear that," returned Lord Hastings. "He is too dangerous a man to be at large. Besides, without him, the Germans will hardly get very far."

He turned to General Hamilton, who had followed him from his room, and added: "If you'll be so kind as to give me a detail of ten men, sir, I'll go and see about this matter. It may be that we can recapture the vessel."

General Hamilton acted quickly. He summoned an orderly and commanded that ten men be placed at Lord Hastings' disposal immediately. The men appeared on the run a moment later and Lord Hastings led them toward the river, where they all embarked in a small motorboat and headed for the spot where they had left the submarine.

But there was no submarine to be found. It had disappeared.

Lord Hastings uttered an exclamation of chagrin.

"They've gone," he said. "Edwards, I guess you didn't hurt Davis very bad. I don't suppose there was a sailor aboard who could navigate the vessel. Davis probably could."

"I'm sorry, sir," returned Edwards.

"So am I," returned his commander. "We'll have to catch that fellow, and it is likely to prove a hard job. However, the sooner we get after him the better."

"And what do you intend to do, sir?" asked Jack.

"We'll take another of these vessels and put to sea again," declared his commander. "We may come up with him sooner than we expect. But—we'll take a British crew this time."

It was now after daylight and Lord Hastings set about his preparations with vigor. Before evening the lads found themselves aboard one of the German submarines that had been captured and brought to the surface. The vessel was manned with a full complement of British underwater sailors. Edwards was among them.

"We'll go down the river immediately," said Lord Hastings, after a tour of inspection of the vessel, "and when we are at sea we'll fly the German flag. None of our submarines looks anything like this craft, so if we come up with the enemy we will be taken for a German. You may steam at ten knots, Mr. Templeton."

Jack gave the order and the vessel moved down the river.

Shortly after nightfall the submarine, U-6, was proceeding into the North Sea, for it was there that Lord Hastings believed he would be more likely to encounter Davis and the U-16.

"Besides," he explained, "our usefulness is not at an end in the matter of obtaining information from the Germans. We may put into Ostend again if necessary."

All during the night, although Frank, Jack or Lord Hastings was continually on the bridge, they did not encounter anything that looked like an enemy ship, although the U-6 dived several times when it drew close to a British ship of war—one of the blockading fleet Had the submarine approached too closely it would have drawn a shot from the battleship, whose commander could not possibly have known that the German submersible carried a British crew in the service of King George.

The following afternoon, having traveled far toward the east, they were to have an adventure.

Moving slowly along, and presenting the appearance, from a distance, of a little speck upon the surface of the sea, the U-6 continued toward the east. Frank had taken the bridge half an hour before and now was studying a faint smudge on the eastern horizon. A moment later and a second smudge appeared and then a third, to be followed almost immediately by a fourth.

"Strange!" he muttered. "Seems to be coming from the direction of Heligoland. Battleships all right, but the question is, British or German? Must be the latter, though how they figure to run the British blockade is more than I know. However, I haven't heard that any of our vessels are this close to Heligoland. It's too dangerous on account of the German mines."

He summoned Jack, who also gazed curiously at the smoke for some moments; but even while Jack gazed, the dim outline of a large battleship came into sight. Soon a second appeared and then a third.

"Must be German," said Jack. "Call Lord Hastings."

Frank did so and soon the commander of the U-6 appeared on deck.

Lord Hastings wasted no time in fixing the identity of the approaching vessels.

"Germans," he said briefly.

"Yes; but where are they going?" Jack wanted to know.

"Probably intend another raid on the British coast," returned Lord Hastings. "By the time they are in waters patrolled by our ships it will be dark, and they hope to pass them in the night. You haven't forgotten the raid on Scarborough and Hartlepool, have you?"

"No, I haven't," said Jack. "But I don't figure they would have the temerity to try another."

"They seem to have temerity enough to try anything," declared Frank. "However, I guess it's up to us to stop this raid."

"Right you are, Frank," said Lord Hastings quietly. "It's up to us."

"And how do you figure we are going to get all four of them?" demanded Jack.

"Well, with luck we might do it," replied his commander. "However, it would hardly be necessary for that. If we can sink two the others will turn and run."

"And shall we remain on the surface, sir?" asked Jack.

"No. We'll submerge until we are close to them. Then we can come up safely enough, for they'll believe us friends. We can sink one and get down again in time. Then, taking our calculations as to where they will be, we can come up again and have a try at another. We may as well submerge now."

Jack gave the order, and a few minutes later the U-6 was beneath the water, not even her periscope being allowed to show. Here she remained until Lord Hastings believed the German battleships had approached close enough to be in range of the submarine's torpedoes. Then she came to the surface again.

Lord Hastings had gauged the distance accurately. The German ships were now hard by and steaming swiftly forward. As the U-6 sprang up from beneath the water, there was some excitement aboard the German vessels, which soon quieted, however, as the Germans made out the lines of the vessel and caught the German flag with their glass.

"We're safe enough," declared Jack. "They take us for one of themselves."

"Much to their sorrow," said Frank.

"All ready below?" demanded Lord Hastings.

"All ready, sir," replied Jack.

"Good. Down with both of you then. I'll be down the moment the first torpedo has been fired, and we'll have to submerge as quickly as possible."

The lads obeyed Lord Hastings' command and took their positions.

"Ready with No. 1 torpedo," came Lord Hastings' command from above.

"Ready, sir," returned Jack, after a quick scrutiny.

"Ready with No. 3 torpedo," shouted Lord Hastings.

"Ready, sir," said Jack, and then exclaimed in an aside to Frank:

"By Jove! He's going to try and get two of them at once."

And such, indeed, was Lord Hastings' intention. The German battleships were so close together that Lord Hastings believed he could strike a double blow successfully and with perfect safety to his own vessel.

Signal flags now were displayed at the masthead of the foremost German battleship and Lord Hastings knew that some answer was expected from the submarine.

"Well, I can't decipher your signals," he muttered, "but I can give you some kind of a reply—which I don't suppose will be much to your liking."

He turned and gave a command to Jack; and Jack, in turn, flashed it upon the electric signal board below with the pressure of a button beneath his finger.

"Attention!" came the command now, displayed in letters of fire.

Then a brief lapse of time, in which all was silence below.

Then another signal showed red on the board.

"No. 1 torpedo! Fire!"

Again came that faint metallic click to which the boys had grown so accustomed, and a terrible engine of destruction sped over the water toward the German ships.

A moment later a second command flashed on the board.

"No. 3 torpedo! Fire!"

Once more the click and then nothing but silence. A moment later Lord Hastings hurried below.

"Submerge!" he ordered.

CHAPTER XXII.

TOWARD OSTEND AGAIN.

Jack had been ready for this command and repeated Lord Hastings' words immediately. Not a second was lost, and a moment later the tanks began to fill and the submarine sank lower and lower in the water.

Jack, who had glued his eye to the periscope, gazed at the German battleships as long as it stayed above water. In the few moments that it took the craft to submerge, he saw that two of the enemy's craft had been struck and that the other two had trained their big guns upon the U-6. His heart beat fast, for he was afraid the submarine would be unable to put a thick enough blanket of water above it to withstand the German shell, should the first shot be gauged accurately.

Just before the periscope disappeared beneath the surface, cutting off the lad's view, he heard the faint sound of a gun. He braced himself for the shock that he expected; but none came. The first shell had gone wide and he breathed easier. Before the second shot came, the U-6 was safe in the depths.

"Pretty close," the lad muttered aloud.

"What was pretty close?" demanded Frank, who had not heard the sound of the shot. "Didn't we hit either one of them?"

"Oh, yes, we got them both," replied Jack. "I was talking about our own escape. The Germans fired one shell at us and they can't have missed very far. Fortunately, we came down before a second."

"Shape your course due east, Mr. Templeton," commanded Lord Hastings at this juncture. "We'll have a try at another of them."

Jack gave the command.

"Twenty knots!" ordered Lord Hastings.

The U-6 leaped forward beneath the water like a thing alive. For fifteen minutes she sped on and then rose until her periscope showed above the surface.

"As I expected," said Lord Hastings. "The enemy is making for home, but we have outrun them and are now between them and their goal." He gauged the range carefully and then ordered: "No. 2 torpedo!"

Again all was expectancy aboard the submarine as all eagerly awaited the next command. It was not long coming.

"Attention!" the signal board read.

And a moment later came the next command:

"Fire!"

A shell sped across the water straight for the third German battleship. Through the periscope Lord Hastings saw the German vessel give a great lurch, then leap almost clear from the water, where it seemed to hang suspended for a full minute, before it came down again. As it did so there was a blinding flash and a detonation that was heard in the submarine.

"Pierced her magazine!" said Lord Hastings quietly.

He stepped aside that Jack might have a look above.

The latter's eyes sought out the spot just in time to see the giant battleship split in twain and disappear beneath the sea. Farther back he saw the two others of the enemy listing badly to port, and knew that they had received their death blow.

The fourth and last vessel was still unharmed and was bearing down on them at full speed. Even as Jack looked there came a puff of smoke from one of her forward turrets and a great splash, less than a hundred yards ahead of the U-6, told that the submarine had been discovered.

"Submerge!" cried Jack.

Lord Hastings repeated the command immediately for he realized that the vessel must be in danger. Even as the periscope disappeared from sight, there was a second flash from the German and a shell glanced off the bow, sending the U-6 staggering and hurling the officers and crew to the floor.

The men picked themselves up quickly and all stood silent for a moment.

"Test the pumps quick!" was Lord Hastings' first command after he had regained his feet.

"No damage there, sir," came the cheering news a moment later.

"Signal the engine room! Something may have given way," ordered Lord Hastings.

This was done, but the engineer reported no damage.

Frank and Jack both breathed easier, as did Lord Hastings.

"A pretty narrow squeak," remarked Lord Hastings calmly.

"Rather, sir," agreed Jack dryly. "And now shall we go after the other one, sir?"

"I guess not," replied his commander. "After this day's work we can afford to let one escape. There is no use taking further chances. Besides, she'll be on the lookout for us and might cripple us the moment we showed ourselves. No; we'll head west again and won't come to the surface until we are well out of this. You may come about, Mr. Templeton, and proceed due west at ten knots."

This was done and the U-6 did not come to the surface again until her commander felt sure that he had no longer need to fear the single remaining German battleship. Then, upon the surface again, Lord Hastings, Frank and Jack ascended the bridge.

Through their glasses, far back, they could still see the German battleships, which, though wounded unto death, were still afloat, apparently battling desperately to resist the sea that was trying to draw them under. The water was still full of bobbing heads—the German sailors who had leaped into the sea.

"Poor fellows," said Lord Hastings compassionately.

"Why didn't the other ship stop and pick them up?" demanded Jack.

"Didn't have time, I guess," returned Jack dryly. "Her commander was in too big a hurry to get away from there. He deserves the same fate for running away from them, if you ask me."

"He certainly does," agreed Lord Hastings. "However, there is nothing we can do for the poor sailors in the water; we have no room for them here. They will have to shift for themselves. It's the fortune of war."

"And now where to, sir?" asked Frank.

Lord Hastings looked at him amusedly.

"I guess that is the hundredth time you have asked me that question," he said. "However, I don't mind answering it, although you will find some day, should you chance to serve under another commander, that such questions are not received with very good grace. I believe we shall take another little run into Ostend."

"Good, sir!" said Jack. "We did very well on our last trip. Perhaps we shall be fortunate enough to learn something this time."

"Who knows?" said Frank, with a shrug of his shoulders. "However, the nearer the enemy we are, the more chance for action. The sooner we get started the better I shall be pleased."

"It's a short run from here," said Lord Hastings, "and I believe we shall be safe enough if we make the attempt in broad daylight. We'll take a chance."

He gave the command to go forward and the U-6 moved swiftly ahead.

As Lord Hastings had said, it was not a long run, and two hours later, standing on the bridge, the boys made out in the distance the lofty spires and steeples that they felt sure was the Belgian seaport. And they were right.

The U-6 was not molested, not even challenged, as she moved slowly into port, flying the German flag, her officers and crew all attired in German uniforms.

"Where are all the big German battleships?" asked Frank in surprise, after sweeping his eye over the water in all directions in a vain effort to locate one of them.

Jack smiled.

"You ought to know there are no German battleships here," he said.

"But——" began Frank.

"The battleships are still safely bottled up in Heligoland," Jack explained. "While Ostend is called a German naval base, it is, strictly speaking, nothing but a submarine base. The under-sea boats have been able to run in here without much difficulty, but the larger vessels could hardly get by on the surface."

"I see," replied Frank. "I hadn't thought of that."

"But it seems to me we are getting in pretty easily," said Jack. "It's a wonder we are not challenged. I'm always suspicious of anything that is attained too easily. I wonder if we can be suspected?"

"Not likely," remarked Lord Hastings. "We've come pretty straight, in spite of our short stop. They could hardly have had word of the sinking of their vessels in the Thames as yet."

"Unless from Davis and his crew, sir," suggested Frank.

"I don't believe they have learned anything from Davis," Jack declared. "That bunch of vagabonds are probably prowling about seeking whom they may devour."

"And I have a faint hope that they may seek to devour us before long," said Frank with a smile.

"I've sort-o had that wish myself," Jack seconded his chum. "However, I feel certain that we shall come upon them sooner or later."

"And still," said Lord Hastings, "there really is no telling where they are likely to be. They can't wander too far from their base. They'll have to put in some place every so often, you know."

"They will live off their victims, providing they have any," said Frank. "To find them is like looking for a needle in a haystack. We might have to search the seven seas."

"And then not find them," Jack added.

"Well, if we do come up with them, I'd like to lay my hands on Davis," declared Frank.

Jack smiled.

"You laid hands on him last time, if I remember rightly," he said. "Also he laid hands on you, and a deal more roughly, too. He might not let you off so easily again."

"Think so, do you," said Frank, a little sulkily. "He was just lucky, that's all."

"It may have been a little luck," Jack admitted. "At the same time, you will have to give the fellow credit. He can use his hands. I guess if we encounter him again it will be up to me to handle him."

"You don't seem to have much confidence in yourself," remarked Frank sarcastically.

"Well, a fellow has to have confidence in this world," was his chum's reply. "It may be that he would be too much for me, too; but I've an idea I could take care of him."

"Well, you won't. He's my meat next time," declared Frank.

"We won't argue about it," smiled Jack. "We'll let events shape themselves when the time comes. Only, if he falls to my lot, I'll try to even up your score, too."

"And if he comes to me," grinned Frank, "I'll put in a few blows for you, seeing that you are so obliging."

CHAPTER XXIII.

AN UNEXPECTED ENCOUNTER.

"Now that we have so kindly been permitted to enter," said Lord Hastings, "I don't believe it would be half a bad idea for us to go ashore; or at least two of us."

"I speak to go with you, sir," exclaimed Frank.

"So do I, sir," said Jack.

"Well, all three of us can't go," Lord Hastings decided. "We'll draw straws to see who are the fortunate—or unfortunate—two. I'll draw with you. The one who gets the short one loses."

He drew three toothpicks from his pocket, and putting them behind his back, broke one. Then he held them out to Frank.

"Pick one," he said.

Frank did so, and glanced at it eagerly. It had not been broken.

"I go," he declared.

"It's between us now," said Lord Hastings to Jack. "Pick one, Jack."

He held up the remaining two toothpicks Jack gazed at them earnestly.

"I'll take this one," the lad said at length, and picked the one on the right.

"You win," said Lord Hastings quietly. "I'm the fellow that must remain behind."

Jack was equally as pleased as Frank, but he did not manifest the same enthusiasm.

"And what is it you expect us to learn, sir?" asked Jack. "I'm sure I haven't any idea."

"Nor I, sir," declared Frank.

Lord Hastings smiled.

"You see," he said, "it might have been better to let me go." Then he added after a brief pause: "I don't know that I had any particular plan in view. I was just going ashore and stroll about a bit. It is barely possible that one of you may overhear something. I wouldn't stay more than two hours at the most." He glanced at his watch. "Two o'clock now," he said. "I shall expect you back here at 4.30 at the latest."

The lads nodded.

"Will it be best for us to row ashore ourselves, sir?" asked Frank. "Or shall we have one of the men take us?"

"You would better go alone," replied Lord Hastings, after a moment's hesitation. "You can tie your boat up some place. I hardly think any one will bother it. A sailor might betray all of us unconsciously. In a game like this, the fewer the better is my motto."

"Come on, Jack; let's be moving," said Frank impatiently. "There is no use staying here all day. Hurry up."

"Now you just hold your horses," replied his chum. "We'll get there soon enough—maybe a little too soon, so far as we know."

Nevertheless the lads wasted no further time in talk and five minutes later the two were rowing shoreward in a little boat.

As they rowed along, they saw several other under-the-sea craft at anchor and upon the bridges of one or two stood officers. These saluted as the boys passed, but none so much as hailed them.

"These German uniforms seem to be pretty good things," Frank remarked in a low voice. "Guess they carry the entrée any place in the town."

"We'll see," returned Jack briefly.

Fifteen minutes later they reached a landing and climbed ashore. Then they tied the little boat up, against their return, and started down the first street.

"Pretty likely looking town, this," declared Jack, as his gaze roved about.

"Yes," Frank agreed, "but you can still see the marks of the German shells that struck during the siege."

They looked around with interest—though not so curiously as to attract attention—and continued along the street.

For an hour and more they strolled about gazing at the various sights of interest, but learning nothing of value. Several times they approached knots of German officers, attempting to overhear their conversation. But there was nothing in any of this street-corner talk which was worth hearing, being concerned chiefly with accounts of adventures and curious episodes.

The lads were saluted frequently as they passed along and they returned these salutes with customary German stiffness. No one spoke to them and for this they were duly thankful, although each spoke German like a native and ran little risk of detection on that score.

Frank glanced at his watch.

"Five minutes to four," he said. "Time to be moving back."

Jack nodded.

"May as well, I guess," he agreed. "If you ask me, this has been an afternoon wasted. I don't seem to have learned anything of importance and I don't believe you have either."

"You've been with me right along," replied Frank. "You know as much as I do."

They retraced their steps toward the water front.

And here, in the place they would have felt least likely to encounter a familiar face, that very thing happened. They were still a short distance from the water-front when a man brushed by them closely, walking rapidly. His head was lowered and his face was well muffled in spite of the fact that the day was not cold. There was something familiar about him, though neither lad could place him. After he had passed both lads turned and looked after him with one accord.

"There is something familiar about that fellow," Jack declared. "I've seen him some place before."

"And so have I," agreed Frank. "And I have a feeling that it was not under very favorable circumstances."

Each lad racked his brain for a brief moment; then Jack said:

"Well, I guess it doesn't make any difference. Let's go."

He turned about and took a step forward. Frank was about to do the same, when a sudden thought flashed into his head.

"Wait a minute," he called. "I think I've got him."

"Who?" demanded Jack.

"Davis!" said Frank quietly. I'll bet a pretty red apple that man is Davis."

"By Jove!" said Jack. "I wonder—now what would he be doing here?"

"I don't know," replied Frank, "but I feel sure that's who it is. Come on. Let's go after him. We'll lose him in a minute."

Even as he spoke the man he felt sure was Davis turned a corner. Not waiting for Jack to agree, Frank hurried after him. Jack followed.

The man ahead was walking rapidly, but the two lads gained on him. After two blocks' walking they were less than fifty yards in the rear—slouching along cautiously, with heads lowered, for they did not wish to be recognized if the man were really Davis.

Once the man turned and gazed at the two figures behind him; then, apparently satisfied that he was not being followed, he moved on again.

After two more blocks he doubled around a corner. Frank and Jack turned the corner a moment later, just in time to see Davis mount a short flight of steps, open a door and enter the house.

Frank and Jack walked by, taking careful note of the number of the house, however, and without glancing up again, continued down the street and turned the next corner.

There they halted as of one mind while Frank peeped around the corner, remarking:

"Don't want him to trick us. I don't think he knew he was being followed, but you never can tell."

The lads stood there for perhaps ten minutes; then Jack reached a decision.

"As long as we have come this far," he said, "we may as well finish this man hunt. We'll go and have a look for him."

"How do you figure we are going to get into the house?" demanded Frank. "Or do you just plan to ring the bell and ask for 'Mr. Davis'?"

"We'll have to get in some way," returned Jack, "or else admit that we are wrong."

"I won't admit I'm wrong," declared Frank grimly. "I feel positive the man is Davis."

"So do I," replied Jack; "else I wouldn't be so keen about getting into that house. We'll go back and skirmish around a bit, anyhow."

They retraced their steps slowly, and passing the house where the man had entered, took careful note of it.

It was a two-story building. Steps led to a porch, not high above the street, but still high enough to make the single window in front beyond reach from the street below. A narrow passage was between it and the house on the left. It was built flush against the house on the right.

At the corner the lads again turned and retraced their steps. "I'm going to try the door," said Jack. "You slink back in that dark alleyway until you hear from me."

Frank signified that he understood, and passing the house, did as Jack had instructed, the latter mounting the steps quietly and swiftly.

The lad laid a hand on the knob and turned it. Then he pushed on the door, but it held fast.

"Locked," he said, plainly disappointed.

There was no window in the little vestibule and the single front window was beyond reach from the porch. Neither was there a transom that could be forced.

"No means of getting in here," Jack told himself.

He descended the steps and joined Frank in the alleyway.

"Well?" Frank greeted him.

Jack shook his head.

"Can't get in that way," he said.

"Well," said Frank, "I have been doing a little exploring while you were up there and I have found a way."

"How?" asked Jack, a little surprised.

For answer, Frank motioned to a little aperture in the side of the house, close to the ground.

"Window into the basement," he explained. "It's open."

Jack wasted no time. He dropped to his hands and knees and, pushing the window open, shoved his feet through. Then he wriggled his body through the opening and dropped.

It was not a hard fall and he picked himself up unhurt. He called softly to Frank and the latter was beside him a moment later. Walking softly, Jack led the way up a little flight of stairs to a door which opened easily. He stepped inside.

Frank followed and Jack closed the door. It was perfectly dark.

But suddenly the darkness was lighted up. The astonished lads gazed into the muzzles of a pair of automatics and a well-known voice cried:

"Hands up!"

CHAPTER XXIV.

ANOTHER UNPLEASANT SURPRISE.

To say that the lads were astonished is putting it mildly. There they were, so they believed, sneaking upon an unsuspecting victim and now they found themselves absolutely in that victim's power, for it took but the first glance to assure them that the face that gazed so evilly and sardonically into theirs was the face of Davis.

Now Davis grinned at them.

"I was expecting you, gentlemen," he said with biting sarcasm. "I did not wish to seem discourteous, which is the reason I welcome you in person. But, also, knowing your kind, I surmised that you would not announce yourselves at the front door, as would most British gentlemen; therefore I receive you here. I assure you you are most welcome."

All this time he kept each lad covered with an ugly-looking automatic.

As neither Frank nor Jack replied, Davis continued.

"I would just like to add that if you desire to get ahead of me it will be necessary to arise very early in the morning. What kind of a spy do you think I am, anyway, not to know when I am being followed? I assure you, gentlemen, you have misjudged me. I was not born yesterday."

Still neither lad replied.

"And now," Davis went on, "I must ask you to be so kind as to precede me to the parlor, where I shall entertain you more comfortably."

He emphasized this statement with a slight gesture with one of his revolvers and there was naught for the lads to do but obey.

Davis followed them closely, still covering them with his two revolvers. In the parlor he motioned them to seats and took a chair across the room.

"Now," he said, "I would be pleased to have you tell me how you escaped from our enemies, the British."

"Well, I can see no harm in enlightening you," said Jack. "I would have supposed that, being so brilliant, you had guessed it by this time. We are British officers and not German."

"Would it surprise you," queried Davis, "if I should tell you I had surmised as much? And our good friend, Commander Bernstorff"—and here Davis laughed—"how is he?"

"Well," replied Jack calmly. "And now I wonder if you would explain a few things to me?"

"You are at liberty to ask," smiled Davis.

"Then, how did you get here—why did you venture here—and what of your little private expedition?"

"Those," said Davis, "are what I should call considerable questions. However, I can see no harm in answering them, particularly as you will never be able to repeat what you hear now. I came here in our submarine the U-16, which, by the way, I have rechristened The Vulture—a suitable name, don't you think?—and I came here because I had business here. Now, as to your other question. Our little privateering expedition is progressing famously. We have already sunk one British ship and secured a quantity of booty, which may have something to do with my presence in Ostend."

"I see," said Jack.

"And," continued Davis boastingly, "I came in right under the noses of the Germans. My submarine lies in the harbor at this moment. I came ashore in the guise of a German officer. I was not questioned, nor were you, I take it?"

His last words formed a question, and Frank answered.

"No, we were not questioned," he said.

"I thought not. Well, when I presently have finished my business—which, by the way, has been increased since your arrival—I shall make my way back to my vessel and put to sea again. I shall bother none of the Germans nor any ships of war unless they bother me—my business is with ships of commerce, where there is booty to be had—and when I have reaped enough I shall go to America, where I shall live the life a gentleman should."

"You'll make a fine gentleman," said Jack sarcastically.

"You think so?" said Davis, apparently unruffled. "So do I. But time presses. I am sorry I can entertain you no longer. You will please precede me from this room and upstairs."

He arose, and with one revolver, motioned the lads out the door. There was nothing for it but to comply; for both lads realized that while they might have jumped Davis, one of them probably would be shot down; nor was it for his own sake that each hesitated.

They preceded Davis up the stairs and into a large unfurnished room. As he entered, Jack looked toward the window. It was heavily barred and the walls of the room, he saw, were very thick. Once locked in that room, the lad realized, there was little hope of escape.

"Now," said Davis, "please cross the room and stand with your backs to me. I shall leave you here to amuse yourselves. You will have lots of time, for, I venture to say, the room will not be entered for months to come—not until I return, which may not be for months. Then I shall give myself the pleasure of calling on you. Now, good-bye. Turn and face the wall, please."

Jack realized that it was now or never and he took a sudden decision.

"Face the wall, Frank," he commanded quietly. "It's no use."

Frank obeyed.

"You too, if you please," said Davis blandly, flourishing a revolver, while at the same time he returned the other to his pocket.

"Look here, Davis," said Jack quietly, "this thing has gone far enough. We have been highly amused with your entertainment, but now it is time to call a halt."

Davis looked at him expectantly.

"Well?" he queried.

"Just this," said Jack calmly. "Unless you drop that revolver this minute, I shall have to take it away from you."

He gazed at Davis steadily.

The latter's shifty eyes could not meet the steady gaze of the lad and he looked away, but kept Jack covered with his revolver.

"Oh, I guess not," he said.

"Oh, yes I shall," said Jack easily.

"Come," said Davis, pulling himself together and raising his revolver so it pointed between Jack's eyes. "Enough of this. Get back there now or I shall fire."

Instead, Jack took a step forward, still looking Davis squarely in the eyes.

"Put down that gun!" he commanded sharply.

His tone startled Davis, and for a brief moment he allowed the weapon to waver; and in that moment Jack leaped upon him.

Taken off his guard, Davis nevertheless still had time to raise the revolver and fire. Jack staggered back as he felt something like a red-hot iron pierce his right arm; and the member dropped limply to his side.

Again Davis fired, but Jack ducked even as he pulled the trigger and the bullet passed over his head.

There was a cry from behind him and Frank pitched forward to the floor. The bullet had struck him a glancing blow on the side of the head.

Jack's heart grew sick as he heard his chum's cry, for he realized in a flash what had happened; but he did not turn his head to look. Instead, stooping low, he leaped lightly forward and seized Davis' pistol arm even as the man fired again. Jack jerked the arm upward at the moment the weapon went off and the bullet passed him harmlessly. Then, with a vigorous wrench, the lad twisted the revolver from Davis' hand and kicked it to one side as it fell to the floor at his feet. Then he struck Davis sharply across the face with his left hand, and as the man staggered back, thrust his hand into the pocket where so recently Davis had placed his second revolver.

Davis grabbed at it but too late.

Jack stepped back and, walking across the room, picked up the other weapon. Then, opening the door, he tossed both weapons outside, closed the door and faced Davis.

"I've still got a couple of guns in my own pockets," he said quietly, "but I'm going to thrash you within an inch of your life without use of a weapon—and with a bad arm besides. I may shoot you later, I haven't decided about that yet. It all depends upon how badly you have hurt my friend here."

He stepped forward and aimed a hard blow at Davis with his left fist. Davis stepped aside and the blow missed. At the same time Davis swung hard with right and left and the second blow caught Jack on the helpless right arm. Jack winced but said nothing. He was deadly cool, and he advanced upon Davis smiling.

"Now," he said, "I'll give you an imitation of how I treat a dog like you."

He backed Davis into a corner of the room by a series of single-arm feints and then struck out heavily. Davis put up both arms to block the blow but it did him no good. His guard was swept away as though it had been a feather and the heavy blow crashed through and caught him in the face.

Davis staggered back with arms covering his face protectingly and again Jack struck him heavily between the eyes. Davis fell to the floor in a heap, where he lay whining. Jack stood over him angrily.

"Get up!" he commanded quietly. "Get up and fight. I'm not through with you yet."

Davis grovelled upon the floor, seeking to clasp the lad's knees.

"Get up!" commanded Jack again.

Davis made no move to rise.

Jack stretched out his uninjured arm and jerked the man rudely to his feet.

"Put up your hands and fight," he ordered. "Don't show yourself the dog you are!"

Davis did as Jack commanded and aimed a blow at the lad's head.

Jack promptly knocked him down again.

A second and a third time this was repeated; but after the last fall Davis grovelled and moaned like a whipped child.

Jack gazed down at him in disgust.

"And I hadn't half begun," he said angrily. "However, I can't stand here and knock down a man who will make no attempt to defend himself. I am through with you now. You can go."

Slowly Davis raised himself to his feet and moved toward the door, looking furtively about as he did so. As he reached the door, he sprang suddenly outside with a loud cry. Jack sprang after him and seized his arm just in time to deflect a bullet he would have fired from a revolver he picked up without.

"I thought so," said Jack grimly. "I thought that was about your size. I had it all figured out, only when it came to a show down I couldn't do what I had intended. I had intended to let you pick up your gun, and when you tried to shoot me, to kill you. But I can't do it. Get out of here now before I change my mind."

Davis started to move along the hall, but at that moment there were heavy footsteps upon the stairs and a moment later a figure in the full uniform of a German battleship commander stood before them.

"What's the meaning of this?" he demanded in a harsh voice.

He glanced at the two quickly, and then realizing that he apparently was talking to a German naval officer, and his subordinate, he addressed Jack.

"You know his Imperial Majesty's orders in regard to fighting with civilians?" he asked.

Jack could do nothing but bow.

"Then," said the commander, "I shall have to place you under arrest!"

CHAPTER XXV.

DOOMED TO DIE.

It was a bitter disappointment to Jack, but he felt he could do nothing but submit. True, he thought to himself, he could probably have attacked the German commander, and perhaps have overcome him; but there was Frank to be considered, and his own injured right arm. No, he felt he could do nothing but submit.

"Very well, sir," he answered the German, "but first you will please permit me to see to my friend."

He indicated Frank's prostrate form across the room. The German saw it then for the first time and nodded assent.

"Also," said Jack, "it would be well if you did not permit that man," indicating Davis, "to escape. He is a traitor."

"So?" exclaimed the officer.

He drew his revolver and mounted guard over Davis.

"There is really no use my guarding you," he said. "Half a dozen of my men are below, so you could hardly escape."

In the meantime Jack bent over Frank and raised his chum's head to his knee. Then he arose, asked permission of the German to leave the room for water. The permission was granted and Jack returned a moment later, his cap filled with water.

He sprinkled the water over Frank's face and soon perceived signs of returning consciousness. Frank drew a deep breath and opened his eyes. Then he pushed Jack aside and sat up.

"What's happened?" he asked in a faint voice.

In a few words Jack explained.

"I remember now," said Frank. "Help me up."

Jack did so and then for the first time Frank caught sight of the German naval commander.

"What's he doing here?" he asked of Jack.

"Oh, he's just arrested us; that's all," said Jack.

"Yes," said the German, "and I must ask you to accompany me now. You shall come aboard my ship until this matter has been investigated thoroughly. I'll take charge of you, rather than to turn you over to the military authorities; for after all you are naval officers and I shall help you if I can. Please precede me; and you too," this last to Davis in a gruffer tone.

All proceeded below, where eight or ten other men stood waiting. Then all marched away.

Reaching the water front all entered a small boat and were rowed toward a submarine, perhaps a quarter of a mile away.

As they passed, Jack noticed the U-6 a short distance away and made out Lord Hastings' figure on the bridge. He raised an arm and waved it. He was not sure that his signal had been seen, but he did not wish to draw further attention to his commander.

Aboard the submarine the German commander had them taken to his own cabin, where he insisted upon his own surgeon dressing Frank's wound and having a look at Jack's arm.

The surgeon pronounced both injuries slight and prescribed rest. Several times Frank caught the German commander looking at him curiously and it worried him somewhat, for there was something familiar about the man, though Frank could not seem to place him.

"I'm just trying to think," said the German to Frank, "where I have seen you before. I don't place your name."

"I can't remember you, sir," replied Frank.

Suddenly the German slapped his thigh. Frank's heart sank for some reason he was unable to explain to himself.

"I have it!" exclaimed the German. "You are the lad whom I captured from a British submarine in the Kiel Canal not so long ago. I remember you well now. You escaped. So you are a British spy, eh?"

"I—I——" began Frank.

The German raised a hand.

"It will do you no good to deny it," he said quietly. "I cannot be mistaken. Besides, I can plainly see now that you are no German; and this supposed-to-be German officer with you is also British. I can see it now. So is the other prisoner, though I cannot see what you should have been fighting about."

Neither Frank nor Jack replied. Each realized that there was no use in entering a denial.

"I'll take my oath I'm sorry for this," said the German. "Of course, you know there is but one thing I can do?"

Frank nodded understandingly.

"You were found within our lines in German uniforms," said the commander. "Therefore you are spies and must be treated as such. I myself shall call a court martial within the hour. You must be shot. The other man will be tried separately, but I have no doubt he will suffer the same fate. Orderly!"

A second officer entered the room.

"Have these prisoners closely guarded and bring them here an hour from now," he ordered. "Then summon the commanders of the other vessels in the harbor. They shall sit on a court martial here. Hurry."

Jack and Frank were led from the cabin and locked in another compartment at the far end of the ship where they sat in silence until they were conducted to the commander's cabin.

And as they gazed about the cabin the eyes of both opened wide in surprise, though they made no sound.

For there, sitting with five other German officers about the table, was none other than Lord Hastings, still wearing his German uniform. He was sitting on the trial board.

The German commander who had captured them presided.

"Bring in the other prisoner," he commanded.

A moment later Davis was led in. The lads saw a surprised expression flash over Lord Hastings' face as his eyes rested on Davis; but he sat still.

Then, suddenly appearing to take a close look at Frank and Jack for the first time, he jumped to his feet and approached them. After a careful scrutiny, he uttered a loud exclamation and turned to the other officers.

"Sirs," he said quietly, "you have indeed made an important capture. These men, although apparently young, are two of the most trusted of British spies. I know them, for I have come in close contact with them," and he glared at them angrily. "So, we have you at last, eh?" addressing the boys, who shrank back in well-feigned alarm.

As for Davis, he said nothing. He had been doing a lot of thinking and had come to the conclusion that it was better to postpone his fate by being rescued with Frank and Jack, if possible; for he had a pretty shrewd idea that Lord Hastings was there for some such purpose.

"So," continued Lord Hastings, eyeing the two lads angrily. "I have you, eh. I would like to put a hole through each of you myself." He half drew a revolver.

The German commander interfered.

"None of that, if you please, sir," he commanded sharply. "They shall have trial; and if they are convicted, as I have no doubt they will be, I shall bestow upon you the doubtful honor of performing the execution."

"And I shall be pleased indeed, sir," replied Lord Hastings with a leer.

The German commander turned from him in disgust.

"It is such men as you, who are a disgrace to the navy," he said quietly.

"Sir!" exclaimed Lord Hastings, facing the German in apparent wrath, though nothing could have pleased him better—things were working out much better than he had dared hope.

"Tut! Tut!" exclaimed the German commander. "I have no time to quarrel with you now. But when the war is over, it will give me much pleasure to put an end to one of your ilk."

"I shall remember that!" exclaimed Lord Hastings. "You shall answer to me, sir."

"When the war is over, I shall be very much at your service," was the quiet rejoinder. "But now to business. Prisoners, you may all stand up together. Your name?" he demanded of Jack.

"Templeton, sir," replied the lad quietly.

"And yours, sir?" demanded the German of Frank.

"Chadwick, sir."

The German turned to Davis.

"Davis, sir," replied the man before the German could propound the question.

"Have any of you prisoners anything to say in extenuation of your actions?"

There was no reply.

"No reason why the death sentence should not be passed upon you?" continued the German.

Still there was no reply.

The German commander then explained what he knew of the three and called for a vote.

"Commander Derndorff?"

"Death!" was the response.

"Commander Hellwig?"

"Death!"

"Commander Berne?"

"Death!"

"Commander Blough?"

"Death!"

"Commander Bernstorff?"

Lord Hastings' response was louder than the rest and he smiled evilly as he cried:

"Death!"

The German commander who had captured the lads made a grimace but said nothing.

He paused a moment and then declared quietly:

"My verdict also is death!"

Lord Hastings, apparently, could restrain his impatience no longer.

"Good! Good!" he cried.

"The sentence of this court martial," continued the German commander unheeding Lord Hastings, "is that the prisoners all be shot at sunrise tomorrow. Commander Bernstorff, since you are so eager to perform the disagreeable duty, you may command the execution; and that your men may think the less of you, as president of this court martial, I order you to choose the firing squad from among your own crew."

Lord Hastings beamed on him.

"It shall be done with pleasure," he declared eagerly.

"And," continued the president of the court martial, "you shall take the prisoners aboard your own vessel and you shall be held responsible for them. I could almost hope they would escape, so that you should suffer," he added to himself.

"Good, sir. Good!" cried Lord Hastings. "I shall remove them at once, sir."

"One thing more," said the commander sharply. "They must not be ill-treated. Understand?"

Lord Hastings' face fell in well-feigned disappointment. He appeared to draw himself together, saluted and said with an apparent effort.

"You shall be obeyed, sir."

"Take them away, then."

Lord Hastings ordered the three marched to the side of the vessel, where they stepped aboard the little boat. Then they were rowed rapidly toward the U-6.

As they neared the submarine, where they knew lay safety, the spirits of the lads soared once more, in spite of their wounds. Frank expressed Jack's sentiments as well as his own when he leaned close to Lord Hastings and muttered:

"Close shave, sir!"

CHAPTER XXVI.

MORE TROUBLE.

"You can believe me or not, but it feels pretty good to be back here."

The speaker was Frank as he stood upon the bridge of the U-6.

"It does, indeed," returned Jack, who stood by his side. "To tell the truth, I was afraid we would never get away. I thought we were goners, sure. And see who we have with us, our old friend Davis."

For Davis at that moment came aboard from the small boat beside the submarine. He grinned at the two boys feebly.

"Well, I'm glad to be back along with you," he said.

"I don't imagine you'll be glad to be back very long," said Jack dryly. "It seems to me you might as well have stayed where you were. The result probably will be the same. Only this time you'll have to face a British court martial and they'll probably hang you."

"While there's life there's hope," Davis spoke sententiously. "Which is the reason I didn't say anything over there."

He waved his hand in the general direction of the German submarine they had so recently left.

"Well, I'm much obliged, I'm sure," said Frank. "If you had spoken when you recognized Lord Hastings, it would have been all off with all of us. However, I'm afraid I shall be unable to speak a word in your behalf."

Davis shrugged his shoulders and turned away as Lord Hastings approached.

"Below with you all, quick!" exclaimed the latter. "Don't you realize you are prisoners? What do you suppose some of these German officers would say if they saw you making so free of this vessel, eh? They'd probably come over to see what is wrong. Get below!"

Lord Hastings spoke gruffly, for he had risked much to assure their safety and he did not wish his plans to go for naught. Frank, Jack and Davis obeyed without a word.

"Now," said Lord Hastings when all were safely below, "we'll have to get away from here."

"There should be no trouble about that," said Frank. "All we have to do is submerge and move off."

"And I suppose these other fellows will remain idle and watch us go," exclaimed Lord Hastings sarcastically. "Don't you believe it. We are likely to have trouble. They'll probably have a shot or two at us and we'll be fortunate if one doesn't strike home. Besides which, if we do get down safely, they'll probably chase us."

"Well, they can't find us under the water," Frank stated.

"Perhaps not," agreed Lord Hastings, "but we'll have to come up some time and when we do they are likely to be waiting for us. However, there is no use hesitating now. Every minute makes our situation more precarious. You may submerge to five fathoms, Mr. Templeton."

Quickly Jack gave the command. Immediately the bridge wound into the little conning tower, which at once closed, and the submarine began to sink gradually.

Lord Hastings glued an eye to the periscope and watched developments above.

"Just as I feared," he exclaimed. "They have seen through our ruse. There is excitement aboard all the enemy. Twenty knots, Mr. Templeton, and shape your course due north."

The little craft leaped ahead as Jack gave the command; and at the same moment a torpedo, fired by the nearest enemy craft, flashed through the water where the U-6 had been a moment before. It was a narrow escape.

A second torpedo flashed above the submarine just as it finally disappeared beneath the water; and a third did likewise.

Lord Hastings drew a breath of relief as he moved from the periscope—he could see no longer, the water having passed over the "eye" of the submarine.

"We're safe enough for the time being, at any rate," he declared. "Keep to your course, Mr. Templeton, until I give the command to alter it."

Jack saluted.

"Very well, sir," he said.

"And now," said Lord Hastings, gazing about, "the question remains as to what is to be done with Davis. Where is he?"

Frank looked about hurriedly.

"He was here a moment ago, sir," he replied. "He was right behind me."

"Well, he's not here now," said Lord Hastings. "There is no doubt about that. However, he can't have gone very far. We'll have a look for him."

Frank followed his commander aft.

They peered into every compartment in that end of the vessel. They searched the engine room and all other sections; but there was no sign of Davis; Lord Hastings scratched his chin in perplexity.

"Now what do you think of that?" he said slowly. "But he was on this vessel and he can't have got off. Therefore he must be here."

"There is one place we haven't looked, sir," said Frank.

"Where?" demanded Lord Hastings.

"Your cabin, sir."

"He would hardly have sought refuge there," said Lord Hastings.

"There is no telling, sir," replied Frank. "We may as well have a look."

"Yes, we may as well have a look," repeated Lord Hastings.

He led the way forward again and pulled up before the door of his cabin, which was closed.

"Now I could have sworn I left this door open," said Lord Hastings.

He laid a hand on the knob and turned it; but the door would not open.

"Hm-m-m," muttered Lord Hastings. "Somebody is in there all right. Guess it must be our friend Davis." He raised his voice and called: "Davis."

There was no reply and Lord Hastings repeated his call. Still there was no response.

Lord Hastings was beginning to grow angry.

"Davis!" he called a third time, and when there was no answer, he shouted: "You come out of there this minute or it will be the worse for you. There is no use pretending you do not hear me. Come out!"

This time Lord Hastings drew an answer.

"Thank you, sir, but I shall remain where I am," came back in Davis' voice. "It's very comfortable in here."

"By Jove! He's a pretty cool customer," muttered Lord Hastings to Frank.

"Yes, he's cool enough," responded the lad, "and cold-blooded, too. Shall we force the door, sir?"

"I don't like to do that," replied Lord Hastings, "but I am afraid it will be necessary. I want to get that fellow tied up safely." He raised his voice again. "Davis," he said, "if you don't open that door immediately, I'll break it down."

"I wouldn't try it," was Davis' response. "I have appropriated a pair of your revolvers here and I'll have a shot at the first head that I see."

This reply threw Lord Hastings into some consternation. He turned to Frank.

"There is no use any one getting hurt on the fellow's account," he said. "He's safe enough in there. Guess we may as well leave him."

"We'll have to get him some time, sir," said Frank. "We might as well do it now and have it over with. Two of us should land him without any trouble."

"You mean one and a half," replied Lord Hastings, smiling. "Don't forget you are hardly whole with that wound on your head."

"I think I can prove a little better than a half, anyhow," Frank smiled back. "Shall we break the door in, sir?"

"I have a better plan than that," replied Lord Hastings. "I'll blow the lock off. Stand back out of range of fire from the door. Davis is likely to shoot through it."

Frank did as commanded, and drawing his revolver, Lord Hastings placed the muzzle against the lock.

There was a flash, a loud report and Lord Hastings leaped quickly backward. And it was well that he did so; for a second later there came a second report and a bullet sped through the thin door and imbedded itself in the wall beyond.

Standing well to one side, Lord Hastings thrust out a foot and kicked the door open.

"Better come out, Davis," he said quietly.

"No, thanks," was the reply. "I'll get the first man who shows his head in the doorway."

Lord Hastings considered this point carefully. Then he said to Frank:

"Well, we've got the door open, but I don't see that we are any better off. We can't go after him. Now what, eh?"

An idea struck Frank.

"You stand guard until I come back, sir," he said, and made his way aft.

Lord Hastings stood his ground.

Frank was back in a moment and again took his stand on the opposite side of the door from Lord Hastings. He held something in his hand, and a long snake-like object seemed to wiggle along behind him.

"What have you there?" demanded Lord Hastings in some surprise.

"Hose, sir," replied Frank calmly.

"And what are you going to do with it?"

"Rout Davis out, sir."

Lord Hastings chuckled.

"I am afraid you won't have much success," he replied. "It's a poor Englishman who can't stand a little cold water."

"Maybe he won't like hot water, though, sir," replied Frank.

Again Lord Hastings looked surprised.

"Oho," he said at length. "Now I see what you are about. Going to scald him a little, eh?"

"That's the idea, sir. I have the engineer's word that this hose will throw a pretty strong stream. Once it hits Davis he'll be glad to come out."

"All right," said Lord Hastings. "Turn it on."

Still standing out of the line of fire, Frank, taking the hose well back from the nozzle, thrust it through the door and turned it on.

A thin vapor rose and the hose grew hot to Frank's touch.

"Pretty hot," said Lord Hastings. "Now if you can just locate him with it, you——"

A cry of pain interrupted him and there was the sound of hurried footsteps within.

"Got him," cried Frank gleefully.

He stepped into the open doorway, and as he did so, Davis raised a revolver and his finger tightened on the trigger. But even as he would have fired, Frank turned the scalding water on him. With a howl of pain he dropped the revolver.

CHAPTER XXVII.

THE PIRATES REAPPEAR.

"You got him, Frank!" cried Lord Hastings excitedly, hopping up and down like a boy. "Keep it on him!"

"You bet I've got him," Frank shouted back. "Slip inside, sir, and get him from behind when I turn the water off."

Lord Hastings did as Frank suggested, and keeping to one side of the stream of hot water, entered the room and drew his revolver.

"All right," he called. "Turn it off. I've got him covered."

Frank shut off the hose and also sprang into the room.

But there was no need for force. Davis had had all the fight taken out of him, for the time being, at least. He lay upon the floor and was writhing about apparently in great pain and moaning feebly. It was plain that the hot water had done its work well.

"I give up," he muttered as Lord Hastings and Frank approached him.

The two leaned down and picked the man up. Lord Hastings looked him over carefully.

"Why, you're not hurt," he said contemptuously. He turned to Frank. "That water can't have been very hot," he said.

"Just hot enough, I should say," the lad returned. "I didn't want it too hot, sir. It would have spoiled his looks, and I want him looking fit when he faces a court martial."

"Very thoughtful of you," said Lord Hastings dryly. "I don't believe he is hurt a bit. But I guess we had better tie him up before he does any more mischief."

"Right you are, sir," replied Jack. "Got any rope?"

"Yes; you'll find a good strong piece in the drawer of my desk there. Get it."

Frank opened the drawer and produced a long, strong rope; and as he would have turned to Lord Hastings he was startled by a sudden commotion, followed by the sound of a fall.

Davis had sprung suddenly to his feet, upsetting Lord Hastings as he did so, and dashed out the door. Frank, dashing forward to intercept him, collided with Lord Hastings, who arose at that moment, and the latter went to the floor again, with Frank on top of him.

By the time they had untangled themselves Davis had disappeared aft.

"After him!" shouted Frank, and dashed down the passage. Lord Hastings followed closely.

Davis made straight for the engine room, why, he could not have told. The man was greatly excited and hardly knew what he was doing. As he crossed the threshold, he collided with Simpson, the engineer, and both rolled to the floor.

"I say! What's the matter here?" demanded Simpson angrily. "What are you jumping on me for?"

"I didn't mean to do it," replied Davis, sitting up; and then getting to his feet.

"And what are you doing in here, anyhow?" demanded the engineer. "No one is allowed in this room."

"I didn't know where I was going," responded Davis.

He leaped suddenly forward, and seizing a heavy iron poker, brought it down heavily on Simpson's head. The man crumpled up on the floor. Quickly Davis whirled about and locked the door, even as Lord Hastings and Jack threw their weight against it. Then Davis laughed aloud.

"Stand back there!" he cried. "Stand back, or I'll smash this machinery so none of us will ever reach the surface."

Frank was for smashing in the door regardless of this threat, but Lord Hastings seized his arm.

"Hold on!" he exclaimed. "The man is crazy enough to do it. We shall have to seek some other method of overcoming him."

"And how are we to get him, unless we go after him, I'd like to know?" the lad demanded angrily.

"There must be some way," was the reply. "We'll wait."

He took Frank by the arm and led him away.

Lord Hastings immediately made his way to Jack's side.

"Shape your course east now, Mr. Templeton," he instructed, "and give the command to rise to the surface."

Jack asked no questions and did as instructed.

"We'll have to take a chance on being clear of the enemy when we go up," Lord Hastings explained. "But we've got to get Davis out of that engine room the first thing we do."

"And how do you figure to do that, sir?" asked Frank.

"By giving him a clear path to the bridge," replied Lord Hastings. "I have no doubt that when he finds we are upon the surface he will leave his retreat and go on deck; then, if there is land in sight, he probably will leap overboard and swim for it."

"But you will not permit him to get away, sir?"

"Not if I can help it. However, I would rather have him escape than let him send us to the bottom; and I have no doubt he will reason along that line. Now, when we reach the surface, we will go to my cabin and remain there until we hear him pass my door."

A few moments later the U-6 emerged from the depths and the three immediately went to Lord Hastings' cabin and closed the door behind them. Lord Hastings gave an exclamation of dismay as he gazed about.

"You certainly did a good job with that hose," he said to Frank. "There is not a nook nor cranny of this cabin you didn't touch. Look at it, it won't dry out in a month."

"Hardly that long, sir," said Jack with a grin. "But tell me what all this is about, anyhow."

Frank explained. Then all grew silent, awaiting the sound of footsteps that they felt sure would herald Davis' flight. And a few moments later they came, creeping along silently.

Frank took a step forward, but Lord Hastings stayed him with a gesture.

"Let him alone," he commanded. "We don't want him to find another hole. We have had trouble enough with him."

A few moments later footsteps sounded on deck.

"Well, he's up there," said Frank. "Now what?"

"Guess we can go up after him now," replied Lord Hastings.

He led the way.

"Careful, sir, when you go up," warned Jack. "He's likely to be waiting for one of us to show a head."

Lord Hastings paid no heed to this command, but sprang quickly up. He gazed around rapidly. There was not another soul on deck.

"Come on," he cried to Frank and Jack.

The latter also sprang up and looked about.

"Where is he, sir?" asked Frank.

"Gone," replied Lord Hastings. "Must have jumped overboard."

He swept the sea with his eyes, as did the others.

"What's that over there, sir?" asked Jack suddenly.

Lord Hastings and Frank gazed in the direction indicated. There a little object could be seen in the water. It had the appearance of a small stick and beside it there appeared a black piece of cloth whipping in the breeze.

"Looks like the periscope of a submarine," commented Frank.

"And it is," declared Lord Hastings. "Below quick!"

Jack sprang down the companionway, closely followed by Frank and Lord Hastings. The conning tower closed behind them.

"Submerge to the tip of the periscope," ordered Lord Hastings, and put his eye to the instrument as Jack repeated the command.

At that moment the other craft bobbed to the surface and Lord Hastings made out that the black cloth that fluttered in the breeze was nothing more nor less than a black flag.

"Pirates!" he muttered. "What! at this age of the world?" and then a sudden thought flashed through his mind.

"I'll wager a farm it's Davis' own crew," he muttered.

"What's that, sir?" asked Jack, who had caught his commander's last words.

"Nothing much; only that Davis has found his own gang," replied Lord Hastings quietly. "Here, have a look."

He stepped aside and Jack took his place at the periscope. The lad uttered an exclamation of surprise.

"By Jove! he has, sir," he ejaculated. "I can see him swimming toward the submarine; and there is a man on the bridge waiting for him. Can't we launch a torpedo at her, sir?"

"I guess we can," replied Lord Hastings. "What do you make the range?"

"Hundred yards, sir," replied Jack. "Number three torpedo, sir!"

Lord Hastings touched a button and the signal board glowed. But even as Jack would have given the command to fire, a new object suddenly rose to the surface of the water and he stayed his hand.

It was a third submarine, and Jack, instead of giving the command to fire, for which the men were eagerly waiting, cried:

"Another submarine, sir! Looks like a German. She's moving toward the pirate, sir!"

Lord Hastings stepped to the periscope, pushing Jack firmly aside.

"We'll move off and let them fight it out," he said. "Full speed ahead, Mr. Templeton!"

CHAPTER XXVIII.

THE BATTLE AND THE ATTACK ON THE U-6.

Another few hundred yards from the two other submarines, Lord Hastings ordered the U-6 brought to a stop.

"We'll stop here a bit and watch the battle," he said.

The U-6 rose to the surface and the three officers ascended to the bridge. The pirate craft, The Vulture, was still upon the surface and they were able to see that Davis at that moment had climbed over the side. Together with the man who was already on the bridge he hurried below.

"Now they will submerge," said Lord Hastings.

He was right, for a moment later The Vulture began to sink lower in the water. At this moment the German craft fired her first torpedo. It struck a hundred yards to the right of The Vulture.

"Poor shooting," declared Jack.

The others nodded.

"She'll do better next time," said Frank.

The lad proved a good prophet for the second torpedo skimmed over the water missing The Vulture by inches. At the same time The Vulture launched a torpedo and the three aboard the U-6 gasped as it seemed that the missile would surely strike home.

But the German submersible swerved just a trifle and the torpedo missed by a narrow margin. At the same moment the German submarine began to submerge. She escaped the fire of the pirate until her periscope also was all that was visible.

Then the pirate rose; a moment later the German craft came from below and both vessels launched torpedoes simultaneously.

Lord Hastings uttered an exclamation of astonishment.

"Of all the remarkable things I ever saw!" he ejaculated.

Frank and Jack were equally astonished; and the reason was this: both torpedoes had gone true and the periscope of each vessel fell away.

"There'll be no more diving," said Lord Hastings quietly.

Now the fighting submarines, both upon the surface, launched torpedo after torpedo at each other. A shot from the pirate struck her adversary a glancing blow on the bow and the head of the little craft ducked a trifle. But she bobbed up serenely again a moment later and returned the fire.

This time her aim had been true and the torpedo grazed the top of the conning tower. The Vulture also ducked, but came up again.

"It all depends upon who gets in the first square shot," said Lord Hastings, and at that moment the square shot struck.

The Vulture, swerving suddenly, barely escaped a torpedo from her foe, while the pirate's next torpedo struck the enemy squarely upon the bridge. There was an explosion and the German craft seemed to leap from the water. A moment later she came down in pieces, blown to atoms.

"It's all over," said Lord Hastings quietly. "Now it is time for us to put an end to that troublesome craft."

He led the way below and gave the order to submerge.

But it appeared that Davis, instead of fleeing as Lord Hastings and the two lads had expected him to do, had determined to square accounts with his British enemies. The Vulture headed toward the U-6.

Before Lord Hastings could give the command to launch the first torpedo, a missile from the enemy carried away the periscope of the U-6.

Lord Hastings gave an exclamation of dismay.

"We'll have to fight it out on the surface," he said quietly.

Now the U-6 launched her first torpedo and missed. A missile from The Vulture struck close to port. Again the U-6 missed and swerved just in time to escape another torpedo from the enemy.

Then suddenly Lord Hastings gave the command to submerge.

The command was obeyed quickly and he explained to the lads.

"We'll try and run closer to him while we're below. They'll be expecting us to go the other way, and if we are not seen the moment we come up we'll take them at a disadvantage. Of course, it's a long chance, but we must do something."

Ten minutes later he gave the order to rise again. There was no response. Again Lord Hastings gave the signal and still the U-6 failed to rise.

"What's the matter?" demanded Lord Hastings quickly.

"Something wrong with the tanks, sir," replied Jack hurrying up at that moment. "I've just had Simpson out and he says he can fix the damage without going to the surface."

"All right," said Lord Hastings. "Then we shall remain stationary until Simpson reports O.K."

Fifteen minutes later Simpson completed his work and again Lord Hastings gave the signal to rise. Slowly the U-6 moved upward.

Suddenly there was a shock that threw all on board to the deck, and the U-6 staggered. For a moment her upward progress was stayed, but for a moment only; then she continued upward and suddenly flashed upon the surface.

Quickly Lord Hastings jumped to his feet, and unmindful of any danger he might encounter, dashed to the bridge. Jack and Frank followed close upon his heels. And there a peculiar sight met their gaze.

To leeward, not half a dozen rods away, lay The Vulture almost upon her side. Half a dozen men were floating in the water and one still clung to the tilting vessel.

Frank uttered an exclamation of astonishment.

"So that's what was wrong," he ejaculated. "We came up directly beneath her, sir."

Lord Hastings nodded.

"And it seems to me we did a pretty good job," he declared. "Now——"

The appearance of one of the crew on deck cut short his sentence. The man approached and saluted.

"Well, sir?" questioned Lord Hastings.

"Boat leaking, sir," was the reply. "Two feet of water in the hold now, sir. We can't stop it. We shall have to take to the boats, sir."

Lord Hastings looked at the man in dismay for the space of several moments. Then he said quietly:

"All right, Jackson. Get out the boats and order the men on deck."

Again the man took the time to salute and then disappeared below. A few moments later the full crew of the U-6 appeared on deck and the boats were quickly gotten out.

"Rifles and revolvers for each man," ordered Lord Hastings.

The men already had armed themselves; so Lord Hastings gave the word to take to the boats. This was done, and pulling away from the rapidly settling submarine, all turned their eyes again to The Vulture.

To their surprise The Vulture was not settling as fast as was the U-6 and several figures could still be seen struggling about on board.

"They are launching the boats, sir," said Frank.

"So they are," replied Lord Hastings. "And they are arming themselves. I guess we shall have to fight this thing out yet. How's your arm, Jack?" he called to the lad, who was in another boat.

"Feels pretty good, sir," was the reply. "Why?"

"And your head, Frank?" demanded Lord Hastings, paying no heed to Jack's question.

"First rate, sir, doesn't hurt a bit."

"All right. Rifles ready, men. We'll swoop down on those fellows before they are prepared to hold us off."

But already they had delayed too long to surround the pirates without a fight. The Vulture's boats were afloat now and were manned by the crew; and from the distance the British could see they were all armed.

Lord Hastings gave his commands quickly.

"Mr. Templeton, make a short detour to the right," he commanded. "Take them from the flank." He motioned to Edwards, who was steering the boat next to his own. Edwards approached. "Climb in there and take command, Frank," said Lord Hastings.

Frank did so quickly.

"Now make a detour to the left," Lord Hastings commanded. "I'll try and hold them off here until you reach a proper position. Then we can bear down on them from all sides."

The first shot of the battle came from the pirates and was fired by Davis himself. A man in the bow of Lord Hastings' boat muttered an imprecation and wrung his hand. The bullet had struck his left little finger and carried the tip of it away.

"Hurt much, Price?" asked Lord Hastings.

"Not much, sir," was the quiet response. "May interfere with my shooting a little though, sir."

"Fire when ready," Lord Hastings commanded his men.

He threw his rifle to his shoulder and it cracked viciously. A man in the foremost pirate boat threw up his arms, sprang to his feet and pitched into the sea head first.

"One less," Lord Hastings muttered to himself.

In the meantime, while Lord Hastings engaged the enemy, Frank and Jack were nearing their respective positions. Jack came into action first, sweeping down upon the enemy from the right.

The forces were about evenly divided, three boats to a side, but it appeared that in men the pirates slightly outnumbered the British.

A man dropped in Jack's boat now, fatally wounded. The others did not even pause, but returned the fire steadily. Another man in Jack's boat dropped his rifle and fell back gasping. A pirate bullet found two victims in Frank's boat and Lord Hastings now suffered the loss of another.

But the enemy was paying for these victims. In the center pirate boat three men were no longer able to handle a rifle, while in the craft to the right two had been wounded. The boat to the left also had suffered.

And all this time the boats had been nearing each other and the crack of the rifles mingled with the hoarse shouting of the German sailors. The British, for the most part, fought coolly and silently, only the groans of the wounded breaking the stillness from their part of the water.

Frank, now that the boats were close enough together not to call for instructions to his men, left them to do their own fighting and opened with his revolver.

Now Frank was a crack shot, as he had proved on more than one occasion, and this time his aim was deadly. He found himself opposite the boat in which Davis stood erect and he picked off the men about the British traitor with ease.

At last there remained but Davis. Frank trained his weapon on him carefully, but at the moment he would have pulled the trigger a bullet struck one of the British sailors in Frank's boat a mortal wound. The man jumped and fell sidewise. The boat tipped over and Frank was flung into the water.

Frank's mouth was open as he went under, and when he came up gasping there was no boat near him. Ahead he could see Davis still standing erect. The latter discovered the lad at the same time, levelled his revolver, took careful aim, and pulled the trigger.

But there was no report. The chamber of the weapon was empty.

CHAPTER XXIX.

THE END OF A TRAITOR.

Frank smiled grimly to himself as he floated in the water.

"No more bullets, eh?" he muttered.

He struck out vigorously, but instead of making for the nearest British boat, he swam directly toward the craft in which Davis remained standing.

"I'll get you this time, Mr. Davis," the lad muttered through his teeth.

Davis saw him coming and something must have told him that this time the lad would overcome him. He stooped over and picked up a second revolver. This, too, he levelled directly at the lad and pulled the trigger. But this weapon also was empty.

Now fear suddenly took possession of Davis. He dropped to the thwart, seized a pair of oars and began to row.

But he had delayed too long; for at that moment Frank's left hand grasped the gunwale. Quickly Davis raised himself in the boat, and, brandishing an oar aloft, brought it down in an effort to crush the lad's head. Frank saw the blow coming and dived just in time. Davis again sat down and began to row.

A minute later Frank came up by the side of the boat and seized it in both hands. In vain Davis tried to steady the craft. Frank's effort was too powerful to resist and the little craft capsized, hurling Davis into the water.

Frank, treading water—now that he had his enemy on even terms—smiled as he waited for the traitor to come up; but what was his surprise when he felt himself suddenly seized by the legs and drawn beneath the surface. So sudden and unexpected was this movement that the lad did not have time to catch a breath before his head went under.

He kicked out desperately with his left foot and felt it strike something soft; and at that moment the hold upon his legs relaxed. The lad rose rapidly to the surface, where he inhaled great draughts of fresh air. Then he swam away a few strokes and waited for Davis to rise, for he knew he could not remain under water much longer.

A head bobbed up close to him, and, swimming quickly forward, Frank struck out heavily with his left fist. The fist came in contact with a face and Frank grinned as he realized that the blow had gone home. Again he waited for Davis to come to the surface.

The latter did so a moment later, but succeeded in dodging the heavy blow that the lad aimed at him. He disappeared again almost immediately and a second time the lad felt himself seized in a tight embrace which drew him under.

Immediately he felt the hold upon his legs relax and a hand seized him by the throat.

This time Frank had taken a breath before being pulled under, for the lad was not to be caught napping twice in the same way, and he felt that he could remain beneath the water as long as his opponent.

But the grasp on his throat was strangling him and the lad realized that desperate measures were necessary to free himself.

He swung his right arm low in the water, at the same moment seizing the hand that grasped his throat with his left. His right hand found its mark and at the same moment the lad gave a quick jerk with his left hand. The grip upon his throat weakened, and, as Frank struck a second time, was released altogether.

Almost immediately, however, a pair of arms closed about his legs again, holding him tight and carrying him down. With his two hands Frank felt about him blindly, and at last encountered a head. He reached farther down and then gripped Davis by the throat with both hands and pressed them together.

Davis was threshing about in the water in an effort to release this desperate clutch without altogether loosening his hold upon the lad. Frank's lungs seemed about to burst now and he struggled desperately to push Davis away from him, at the same time maintaining his grip. Things grew blacker than ever beneath the dark water; and then, suddenly, the lad lost consciousness.

When Frank opened his eyes again he found himself in a small boat, with nothing in sight but blue water and the sun beating down upon him, shielded slightly from his face by what he took to to be a coat. The lad rubbed his eyes and attempted to sit up; then fell back with a faint moan.

This sound brought a second figure to his side and Frank felt a hand upon his head as a well-known voice said:

"How do you feel, old man?"

Frank recognized the voice instantly. The speaker was Jack. Things came back to Frank immediately and with an effort he sat up.

"How did I get here?" he demanded. "The last I seem to remember is tipping Davis out of a boat. Then what happened?"

"Then you don't remember a struggle beneath the water?" asked Jack.

Frank racked his brain and a moment later it came back to him.

"Yes, I do," he replied. "I remember he seized me by the legs and I went under. Then I grabbed him by the neck and tried to push him away, but he clung and clung—and clung—and clung—and that's all I can remember."

"And no wonder," declared Jack. "You were under water for five minutes before I could get to you. I got you as you were going down for the last time. I didn't arrive a minute too soon."

"And where are we now?" asked Frank.

"In one of the small boats, making for shore."

"What shore?"

"Any shore. Belgium, most likely. But a storm Is brewing and——"

A sudden shout interrupted him.

"Vessel approaching off the port bow, sir!" came the cry.

Jack stood up hurriedly and looked across the sea. Sure enough, just appearing over the horizon, a faint speck had become visible. Jack waved his hand to Lord Hastings, who was in a second boat not far behind.

"Safe now, I guess, sir," he called.

"Unless it happens to be a German," returned his commander.

"Hardly, in this part of the sea," declared Jack.

The heads of the small boats were turned and they made directly for the approaching vessel, which loomed larger and larger in the distance.

Jack returned to Frank's side.

"Ship, eh?" asked Frank feebly.

"Yes," replied Jack.

"British?"

"Haven't been able to make her out yet. Probably is, though. I hope so, for I want to get you to bed where you can be looked after."

"Don't mind me. Say, how many men did we lose?"

"Ten," said Jack slowly.

"Ten," repeated Frank. "It was a costly battle, wasn't it? But what has happened to——"

"Don't you think you had better not talk any more now?" said Jack, raising a silencing hand. "You're pretty weak. Don't exert yourself."

"But wasn't that Lord Hastings' voice I heard just now?"

"Yes, it was."

"By George! I'm glad he came through safely," declared Frank feebly.

"All right. You try and go to sleep now."

Frank opened his lips to protest, but he was too weary to do so. Several times a question struggled to his lips, but the effort to speak was too great and directly he fell asleep.

It was almost an hour later that the vessel, which those in the little boats some time before had made out to be a British merchantman, sighted them. Immediately small boats were lowered over the side and made toward the shipwrecked sailors.

The latter were quickly transferred to the merchantman's boats and were rowed back toward the steamship. There the wounded were lifted gently over the side and sent immediately to the sick bay, where their wounds were dressed.

The captain of the vessel led Lord Hastings and Jack to his cabin, where he insisted upon an account of their adventures. He was greatly interested and commended Jack highly when Lord Hastings had concluded his recital.

"I must also congratulate your second officer when he has recovered," he said.

"But tell me, captain," said Lord Hastings. "Where are you bound?"

"London," was the reply.

"So? But you were headed in the other direction."

"So I was; but that was merely to avoid the German submarines. I am doubling back now, having changed my course no sooner than I picked you up."

"That is indeed fortunate for us," declared Lord Hastings. "We shall all be glad to get back to London."

"And you shall be there shortly, unless we are unfortunate enough to encounter one of these under-sea murderers," replied the captain.

Lord Hastings and Jack now excused themselves and the latter immediately made his way to the sick bay, where he asked permission to see his chum. This was readily granted.

Frank had not awakened while being transferred from the small boat to the steamship, and again he was filled with curiosity. Jack explained the transfer, and then asked:

"How do you feel now, old man?"

"Better," returned Frank briefly; "and by the way, how's that injured arm of yours?"

"First rate," laughed Jack. "To tell the truth I had almost forgotten I had it, although in the battle it did interfere with my shooting somewhat—and you know I'm not the best shot in the world, anyhow."

"Say," said Frank, "I've got something on my mind that I want to ask you and I can't think what it is."

"Don't worry about it now, old man," said Jack. "Get a little more rest and then it will come to you."

Frank chafed as he struggled with his thoughts.

"No use," he said. "I can't think of it."

"Well, you go to sleep," said Jack. "I'll come back after a while."

He turned and moved toward the door; and as he would have passed out, Frank hailed him.

"Hold on there!" he called. "I've got it."

"Got what?" demanded Jack.

"The question I want to ask you."

"Well, let's have it."

"What happened to Davis?"

"Dead," said Jack quietly. "You proved the better man."

He turned and left the room while Frank lay still, thinking.

And so we shall leave them for a brief time. Their further adventures will be found in a succeeding volume, entitled:

"THE BOY ALLIES IN THE BALTIC; or, Through the Ice to Aid the Czar."

***

CONTENTS