“Our prisoners probably have left all the boats we need,” Jack returned.

“That’s so,” said Frank.  “Funny I didn’t think of that.  Will you be our guide, Cutlip?”

“Glad to be,” was the reply.  “I want to redeem myself in some way.”

“Let’s be moving, then,” said Frank, starting for the door.

“Hold on,” said Jack “We’ve got to take a force with us, you know.  Mr. Hetherton, I’m going to leave you in command of the ship this time.  I shall command the shore party.”

Lieutenant Hetherton’s face fell, but all he said was: 

“Very well, sir.”

“In the meantime,” said Jack, “pick fifty men and set them ashore.  We’ll be there directly.”

Lieutenant Hetherton saluted and left the cabin.

Half an hour later Jack led his men around the reef.  There, a scant hundred yards from shore, lay the submarine.  The little party moved silently to the edge of the water, and as silently embarked in the half a dozen small boats they found there.

“Push off!” Jack commanded in a whisper.

Now young Cutlip had been left behind, but the father had elected to go with the men in the boats.  So earnest was his plea that Jack did not have the heart to refuse him.

A dim light showed on the bow of the submarine as the little flotilla approached; and then so suddenly that the night appeared to be lighted up by magic, a flare of white made the boats approaching the submarine as plain as day.

The submarine’s searchlight had been turned on them.

“Down men,” cried Jack.

The men, or those of them who were not needed at the oars, dropped to the bottom of the boats.  But the distance was so close that those on board were able to make out the fact that the boats approaching were not filled with their own men.

“Americans!” was the cry that carried across the water.  “Man the forward gun there!”

“Fire, men!” cried Jack in a loud voice.  “Sweep the deck with your rifles.  Don’t let ’em bring that gun to bear.”

There was a crash of rifles as Jack’s command was obeyed.  Nevertheless the Germans succeeded in training their rapid-firer, and it crashed out a moment later.  A veritable hail of bullets flew over Jack’s men.

At a quick command from the lads, the boats drew farther apart, thus making the task of the enemy more difficult.  Then they closed in on the submarine from both sides.

Harsh German cries and imprecations were wafted to the ears of the British as the boats drew closer.

“Submerge!” shouted a voice.

“Quick, or we shall be too late,” Jack roared.

The men at the oars exerted themselves to further efforts.  Then Jack caught another cry from the submarine.

“We can’t submerge.  The tanks are still broken.”

“Good!” said Jack to himself.  “Now I see what the trouble is.  Faster,” he cried to his men.