“Mr. Templeton,” said Lord Hastings, “you will have one of the small boats stocked with provisions and water sufficient for twenty-four hours. We shall not submerge until our prisoner has left us.”

Jack saluted.

“Very well, sir,” he said, and disappeared below.

It was but the work of minutes to water and provision the small boat, and when at last all was in readiness, the boat was lowered into the sea. The prisoner climbed in and took up the oars that had been furnished him.

“Goodbye,” he called to the three officers. “Thanks for your hospitality. I hope to be able to return it some of these days.”

“I hope you will never have to,” Lord Hastings called back. “Goodbye.”

The German waved his hand in reply, and the three aboard the bridge of the D-16 waved back at him. Then he bent to his oars, and set out in a direction that, barring accident, would take him to Heligoland.

“Good luck to him,” said Jack, as the German rowed away.

“The same,” said Frank.

“Now,” said Lord Hastings, “for that long deferred dive.”