“But you can’t stay there forever, and you can’t submerge,” said Frank.  “Come up and surrender.”

To this the lad received no response.  Frank reported to Jack.

“So they won’t surrender, eh?” said Jack.  “Then we’ll go down and get them.”

“Rather risky, Jack,” Frank warned.

“So it is,” Jack agreed.  “So’s the whole war.  But wait.  We’ll see.”

CHAPTER XVII

CAPTURE OF THE SUBMARINE

Captain Griwsold aboard the Ventura had watched the struggle on the submarine with eager eyes.  His fingers clenched and unclenched.

“I’d like to get into that,” he muttered.  “I guess I’m not too old.”

Abruptly he turned to the first officer.

“Lower a boat,” he said.  “I’m going aboard the submarine.”

The first officer protested.

“But the passengers—­” he began.

“The passengers be hanged,” said the captain of the Ventura.  “Besides, we’re safer here under the nose of this destroyer than we would be prowling off by ourselves.”

The first officer protested no longer.  A boat was lowered and Captain Griswold and half a dozen sailors climbed in and put off for the submarine, where they arrived just in time to overhear Jack say that if the Germans in the submarine didn’t surrender they would go after them.  Captain Griswold laid a hand on Jack’s shoulder.

“You’re some scrapper, youngster,” he said.

Jack was thus made aware for the first time that the Ventura had not rushed for her home port.

“I thought you’d gone, Captain,” he said.

“I was on my way,” said the captain of the Ventura, “until I saw you fighting these murderers single-handed.  I came back to see if I could help.”

“Thanks,” Jack laughed, “but I guess there are enough of us to attend to them without you, Captain.”

“I’m not sure about that,” declared Captain Griswold.  “I just heard you say you were going below after those fellows?”

“Well?” questioned Jack.

“Pretty risky,” responded Captain Griswold, shaking his head.  “How do you figure to get ’em?”

“Rush ’em,” said Jack briefly.

Again the captain of the Ventura shook his head doubtfully.

“Too risky altogether,” he declared.  “The first one of you that shows his head down there will be potted, sure as fate.”

“But we’ve got to do it, Captain,” said Jack.  “How else is it to be done?”

“Well,” said Captain Griswold, removing his cap and scratching his head, “I guess I can suggest a way.”

“I’m open to conviction, Captain,” said Jack.

“Aboard my ship,” went on Captain Griswold, “I have a supply of a certain sort of gas which, if used properly, will do in minutes what it may take you hours to accomplish.”

“By George!” said Frank.  “Kill ’em all at once, eh?”