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!"

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.

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."

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!"

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.