into the mirror on their own wall, but
they gave no indication of observing anything out of the ordinary.

The mirrors were fastened in a tilted position to prevent them from
swinging as the ship rolled, and as they did not sway there was an
unchanged view to be had.

"I wonder what they're saying," observed Blake.

They could only guess, however, for though the men talked rapidly and
eagerly, as evidenced by their gestures, what they said was not audible.
Though both transoms were open, no sound came from the room opposite
where the boys were gathered. The men spoke too low for that.

"I guess they know it's dangerous to be found out," said Joe.

"But we ought to find out what it's about!" declared Macaroni.

"Yes, I think we ought," assented Blake. "This Frenchman has been in our
country, going about from camp to camp according to his own story, and
he must have picked up a lot of information."

"And he knows about our pictures, too!"

"Well, I don't imagine what we have taken, so far, will be of any great
value to Germany, assuming that Lieutenant Secor is a spy and has told
about them," Blake said.

"We've got to find out something about this, though, haven't we?" asked
Joe.

"I think we ought to try," agreed his chum. "Perhaps we should tell
Captain Merceau. He's a Frenchman, and will know how to deal with
Secor."

"Good idea!" exclaimed Joe. "If we could only get him down here to see
what we've seen, it would clinch matters. I wonder----"

But Joe ceased talking at a motion from Blake, who silently pointed at
the mirror. In that way they saw the reflection of the men in the other
cabin. They arose from their seats at the table, and the map or whatever
papers they had been looking at, were put away quietly in the
Frenchman's pocket.

He and the German, as the boys decided to call Labenstein, spoke in
whispers once more, and then shook hands, as if to seal some pact.

Then, as the boys watched, Lieutenant Secor opened the door of the
stateroom, which had been locked. He stepped out into the corridor, and
was now lost to view.

The next moment, to the surprise of Blake and his two friends, there
came a knock on their own door, and a voice asked:

"Are you within, young gentlemen of the cameras? I am Lieutenant Secor!"

CHAPTER VII

"PERISCOPE AHOY!"

Sudden and unexpected was the knocking, and it found the boys unready to
answer it. They had no idea that the conspirators--either or bo