“Oh, I guess not,” replied Frank, feeling quite well pleased with himself.

“You little Dutchman!” exclaimed Davis.

“Go hunt a hole and go to bed,” said Frank.

There was no danger of his getting angry, for he was too amused.  “If you don’t,” he continued, “I’ll come out there and chuck you overboard.”

“Oh, you will, will you?  Well, come out here and I’ll show you.”

“Some other time,” said Frank cheerfully.

“Right now I am going to turn in.  Pleasant dreams to you, Mr. Davis.”

Davis was very angry now.  Outside the door he stamped his feet one after the other and rattled the knob vigorously.

“Let me in there, or I’ll break this door down,” he said fiercely.

During all this conversation Jack had shed his shoes and outer garments and was about ready for bed.  He now decided that the affair had gone far enough and stepping forward called through the closed door: 

“That’s enough, Davis.  Keep quiet, or I’ll take a hand in this myself.  If I do, you’ll be sorry.  Get away from that door!”

And Davis subsided.

CHAPTER XVI.

AN ENEMY SUNK.

“Steamship off the port bow, sir!”

Frank gave the hail from the bridge.  A moment later Lord Hastings emerged from the little conning tower.  For several moments he gazed searchingly across the water through his glass.

“Britisher,” he said finally.  “Guess we had better submerge.”

“Why, sir?” demanded Frank.  “Surely we have nothing to fear from one of our own vessels.”

“You seem to forget about this German flag we carry,” said Lord Hastings; “also, that, so far as we know, there are no British submarines in these waters.”

“That’s so, sir.  I had forgotten just who we are supposed to be.”

“We’ll go below,” said Lord Hastings.

He moved toward the conning tower, but even as he would have descended below, Frank gave a sudden cry.

“Submarine approaching the steamer, sir.”

Lord Hastings immediately turned his gaze toward the vessel again.  Frank had spoken truly.  Halfway between the steamship and the U-16 a second submarine had suddenly appeared.  Even from where he stood, Lord Hastings could see that the steamer had been ordered to halt.

“By Jove!” he exclaimed.  “They’re going to sink her!”

Jack came on deck just in time to hear his commander’s last words, and he took in the situation at a glance.

“And we can’t remain here idly and let a thing like that happen,” he declared.  “Come, sir, we’ll go below and we’ll have a shot at our German friend there.”

“You forget,” said Lord Hastings dryly, “that for the moment we are one of our friend, the enemy.”

“But we can’t let them sink the liner, sir!” exclaimed Frank in dismay.  “We can creep up on them and launch a torpedo, sir.”