nder or on that waste of waters they believed a deadly
submarine was lurking, awaiting the favorable moment to send a torpedo
at the ship.

CHAPTER XI

THE DEPTH CHARGE

Charlie Anderson, who had taken the earliest watch, roused Blake at the
appointed time, and reported:

"All quiet so far."

"Then you haven't seen anything of our friends across the hall?"

"Not a thing. Just as we arranged, I've had my eye at the hole, but
their doors have both been closed. Maybe you'll have better luck."

"I don't think it will be good luck at all to see one of them sneak out
to flash a signal to a waiting submarine, or one that may be following
us all the while, waiting for a chance to strike. But I will call it
exceedingly good luck if we can stop it," said Blake.

"Go to it, old top!" exclaimed Macaroni, dropping into what he thought
the latest English slang. "I'm going to turn in."

The lanky helper of the moving picture boys had spent the hours of his
watch with his eye close to a small hole that had been bored in the door
of the boys' stateroom. The hole gave a view of the staterooms of
Lieutenant Secor and Mr. Labenstein, which adjoined. And, as Charles had
said, he had not observed either man leave his apartment.

If what the boys had only guessed at were true--that one or both of the
men contemplated giving a signal to the enemy by means of the
flashlight--the time for it had not yet come.

"Well, I'll try my hand," Blake said. "You turn in, Mac, and if I need
any help I'll call you. If I don't see anything up to about one o'clock
I'll let Joe do his trick. Good-night and pleasant dreams."

Charlie did not answer. He was already in his bunk and asleep, for he
was tired, and the last half hour of his watch he had kept himself awake
with difficulty.

Then Blake began his turn of duty. He took a position at the door where
he could look out through the hole into the dimly lighted corridor. He
had a view of the doors of the staterooms of the two men who were under
suspicion, and as soon as either or both of them came out he intended to
follow and see what was done.

For an hour nothing happened, and Blake was beginning to feel a bit
sleepy, in spite of the fact that he had rested during the early part
of the evening, when he was startled by a slight sound. It was like the
creaking of a rusty hinge, and at first he thought it but one of the
many sounds always more or less audible on a moving ship.

Then,