turned to the
boys and said: "It may be a difficult and trying duty to you to perform,
but it is the only safe thing to do. As you know almost every part of
the submarine from the investigation you have made, I would ask you to
follow me, and I will tell you what to do."

The boys nodded their heads, and entered the conning tower with the
captain. The latter turned, before descending, and said:

"You will have observed, no doubt, that the scheme was to turn over the
submarine to us as soon as possible, leaving a time fuse, which, within
a specified time, would have blown the ship to atoms. By so doing they
would accomplish two purposes, namely, destroy the ship, and save their
own lives. We must not put confidence in any statement they may make."

"But wouldn't it be a good idea to let the sub-lieutenant remove the
fuses, as he said he would do?" asked Ralph.

"Would you be willing to rely on that?"

"Well, I wouldn't," replied Alfred. "I could tell by the way the
sub-lieutenant acted that he would play a trick if he could."

"That is just why I want you to assist me in check-mating," said the
captain.

"Tell us just what to do, and you may depend on us," replied Ralph.

"As you know many of the dark places below I want you to go down with me
and find several where you can secrete yourselves. I will then send the
sub-lieutenant down, and order him to remove the fuses. I want you to be
particular to observe every step he takes, and, as far as possible, note
what he does at each place; do you understand?" said the captain.

"Perfectly," replied Ralph.

Together they descended. All were well aware that the lieutenant, the
doctor, and the three wounded men were still in the dining galley, the
door of which had been closed and locked by orders of the captain, after
the last of the submarine crew reached the upper deck.

"I know one good place where a fellow can hide and still see what is
going on," said Alfred.

"Where is that?" asked the captain.

"At that tank by the side of the dining galley," replied Alfred.

"That would be a good vantage point," answered the captain. "It is the
aft trimming tank, and if you can find a place of concealment it would,
at the same time, enable you to overhear any conversation that might
possibly take place, when the sub-lieutenant is performing his unwelcome
duty."

"Then maybe I ought to get somewhere forward of the main hatch?"
proposed Ralph.

"I suppose you have you