obeyed; and the key
held by M. Lecoq, pulled aside from the lock, slipped along the door,
and traced upon it a diagonal scratch, from top to bottom, the exact
reproduction of the one in the photograph.

"Oh, oh, oh!" exclaimed Fanferlot in three different tones of
admiration, as he stood gazing in a revery at the door.

"Do you begin to understand now?" asked M. Lecoq.

"Understand, patron? Why, a child could understand it now. Ah, what a
man you are! I see the scene as if I had been present. Two persons were
present at the robbery; one wished to take the money, the other wished
to prevent its being taken. That is clear, that is certain."

Accustomed to triumphs of this sort, M. Lecoq was much amused at
Fanferlot's enthusiasm.

"There you go off, half-primed again," he said, good-humoredly: "you
regard as sure proof a circumstance which may be accidental, and at the
most only probable."

"No, patron, no! a man like you could not be mistaken: doubt no longer
exists."

"That being the case, what deductions would you draw from our
discovery?"

"In the first place, it proves that I am correct in thinking the cashier
innocent."

"How so?"

"Because, at perfect liberty to open the safe whenever he wished to
do so, it is not likely that he would have brought a witness when he
intended to commit the theft."

"Well reasoned, Fanferlot. But on this supposition the banker would be
equally innocent: reflect a little."

Fanferlot reflected, and all of his animation vanished.

"You are right," he said in a despairing tone. "What can be done now?"

"Look for the third rogue, or rather the real rogue, the one who opened
the safe, and stole the notes, and who is still at large, while others
are suspected."

"Impossible, patron--impossible! Don't you know that M. Fauvel and his
cashier had keys, and they only? And they always kept these keys in
their pockets."

"On the evening of the robbery the banker left his key in the
secretary."

"Yes; but the key alone was not sufficient to open the safe; the word
also must be known."

M. Lecoq shrugged his shoulders impatiently.

"What was the word?" he asked.

"Gypsy."

"Which is the name of the cashier's grisette. Now keep your eyes open.
The day you find a man sufficiently intimate with Prosper to be aware of
all the circumstances connected with this name, and at the same time on
a footing with the Fauvel family which would give him the privilege
of entering M. Fa