awash or resting on the surface.

[Illustration: THE INTERVIEW WITH THE GERMAN CAPTAIN (missing from
book)]

"So you have recovered from your little involuntary rest," exclaimed
Schwalbe in excellent English. He was a remarkably good linguist, for
previous to the outbreak of the war he had been the skipper of a
North-German-Lloyd boat. By sheer good luck he had reached a home port
the day after the momentous declaration of hostilities, having narrowly
escaped capture by a British destroyer.

Owing to the great expansion of the German submarine service, and its
equally rapid reduction at the hands of the British Navy, the supply of
specially trained officers of the Imperial Navy for this branch had run
out. More had been transferred from the pent-up High Seas Fleet, while
others had been absorbed from the now useless German Mercantile Marine,
and hastily put through a course of instruction. Schwalbe was one of
these, and after less than two months' hazardous work in the capacity
of Unter-leutnant found himself in command of U75, one of the "last
words" of von Tirpitz's piratical fleet.

Neither Ross nor Vernon replied. They could form no suitable answer.
It was no doubt very considerate on the part of the Kapitan to enquire
after their healths, but somehow the lads felt that the skipper of U75
was responsible for their presence on board.

"Come, come," continued Schwalbe. "Don't be sulky."

"We are not," expostulated Ross.

"I'm glad to hear it," rejoined the Kapitan, with a grin that had the
effect of letting his cigar fall to the deck. He stooped to retrieve
it, but, suddenly remembering that it was beneath his dignity, changed
his mind and kicked the glowing stump on one side. Having taken
another from a gun-metal case, he lit it with a device that merely
smouldered instead of giving a bright light.

"It is as well we understand each other," he continued. "Do you know
why you are on board U75?"

"No, sir," replied Ross.

"Neither do I," rejoined Schwalbe with astonishing candour. "I wish I
had not been honoured with your company."

"The remedy is in your hands then, sir," said Trefusis. "You can land
us the next time you put in at St. Mena's Island for petrol, or else
put us on board the first fishing craft we fall in with."

"I beg to differ," was the rejoinder. "Unfortunately you are on board,
and you must make the best of it, I understand from my friend--shall I
say Dr. Ramblethorne--that