and Kapitan Schwalbe resolved to make for the Bristol
Channel, where the dangers of being destroyed by modern mosquitoes were
more remote.

Meanwhile Ross and Vernon had been sent back to the quarters in the
alley-way, by the side of the motor-room. Not knowing the reason for
the U-boat's sudden submergence, and consequently unaware of the danger
that threatened her, they formed the erroneous impression that the
submarine was about to attack.

"The old fellow gave us a pretty straight tip," remarked Vernon, when
the chums found themselves alone. "All the same, I vote we get out of
it at the first opportunity, favourable or otherwise."

"'Ssh," whispered Ross. "Someone might be listening. I don't see how
you propose to clear out, though."

"We were on deck just now."

"We were," agreed Trefusis.

"It was fairly dark. All the men up for'ard were lying down. It would
have been an easy matter to have dived overboard and swum for it, if we
hadn't been twenty miles or more from land."

"There was a bright look-out kept, all the same," objected Ross. "And
I wouldn't mind saying that if the submarine were closer inshore,
getting a supply of petrol, for example, we should be closely watched.
All the same, I'm with you if we get the ghost of a chance. But it's a
rummy affair altogether. Fancy that chap knowing our names and the
rank of our respective fathers."

"Ramblethorne must have told him that," said Vernon.

"I suppose so; but for what reason? By Jove, if we get out of this
mess all right, we'll have something to talk about--having been
prisoners on a German submarine!"

The lads were not allowed on deck again that night. Acting upon Haye's
suggestion they "turned in", and slept fitfully until awakened by the
noise of the watch being relieved.

The seaman, Hans Koppe, brought them their breakfast. The meal
consisted of fish, coffee, and the usual black bread. By this time the
captives had practically recovered from the effects of the injection.
Haye's head was still painful, although the headache had left him.

They ate with avidity, owing possibly to the atmosphere of the confined
space, which was highly charged with oxygen.

"What is the Captain's name?" asked Ross, when the man came to remove
the breakfast things.

The sailor told him.

"Where are we now?" enquired Vernon.

The man winked solemnly.

"Afloat," he replied. "Be content with that."

Just then there were unmistakable sign