THE BOY ALLIES UNDER THE SEA

Or, The Vanishing Submarines

by

ENSIGN ROBERT L. DRAKE

Author of The Boy Allies in the Baltic, The Boy Allies on the North Sea Patrol, The Boy Allies Under Two Flags, The Boy Allies with the Flying Squadron, The Boy Allies with the Terror of the Seas

A.L. Burt Company New York

1916



CHAPTER I.

A MYSTERY.

"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."