"Upon my word!" he remarked. "Really, Leslie, you will have something to remember. Experiences like this don't fall to the lot of many youngsters, you know."

"More exciting than that scrap on Blackstone," rejoined Leslie. "Even George would have to admit that. Makes a fellow feel quite bucked. But what do they intend doing with us, I wonder?"

"Events will prove that," replied the sub gravely. "Recollect that we have to conceal our identity as much as possible. These chaps must not be allowed to find out that I am a naval officer. Hark!"

A rasping sound, as the bolt securing the door was shot back, interrupted the conversation before Sefton had time to mature his immediate plans. The metal panel slid open and a petty officer appeared and spoke rapidly in German.

Drowned by the noise of the machinery, the words were inaudible, but by the man's gestures the prisoners clearly understood that they had to follow him. Along a narrow, steel-enclosed passage, then through a maze of intricate machinery, the sub and his brother were conducted, until they found themselves in a small cabin almost immediately underneath the grating that formed the floor of the raised conning-tower.

"You will at once take off your clothes," ordered the petty officer.

At this unexpected command the brothers looked at each other in surprise. The order could not be ignored, despite its apparent inconsequence. However unwilling to submit to the indignity, the prisoners obeyed promptly.

Under the stern glare of the German petty officer, Jack Sefton stripped off his brown jersey, shirt, and singlet.

"Rough luck!" he muttered. "Now these brutes will tumble to it; my name is marked on each of these garments."

Which was exactly what the Huns were intent upon finding out, for, giving a keen glance at the tell-tale lettering, the petty officer without waiting for the rest of the disrobing process made his way aft.