“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 N 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:

“N 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 N 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!”