fear of awakening the boy in the ante-room,
in order to rifle his own money-safe, had every reason to tremble, to
hurry, to hastily withdraw the key, which, slipping along the lock,
scratched off the varnish."

Resolved to unravel by himself the tangled thread of this mystery, the
detective determined to keep his conjectures to himself; for the same
reason he was silent as to the interview which he had overheard between
Madeleine and Prosper.

He hastened to withdraw attention from the scratch upon the lock.

"To conclude," he said, addressing the commissary, "I am convinced that
no one outside of the bank could have obtained access to this room. The
safe, moreover, is intact. No suspicious pressure has been used on the
movable buttons. I can assert that the lock has not been tampered with
by burglar's tools or false keys. Those who opened the safe knew the
word, and possessed the key."

This formal affirmation of a man whom he knew to be skilful ended the
hesitation of the commissary.

"That being the case," he replied, "I must request a few moments'
conversation with M. Fauvel."

"I am at your service," said the banker.

Prosper foresaw the result of this conversation. He quietly placed his
hat on the table, to show that he had no intention of attempting to
escape, and passed into the adjoining room.

Fanferlot also went out, but not before the commissary had made him a
sign, and received one in return.

This sign signified, "You are responsible for this man."

The detective needed no admonition to make him keep a strict watch. His
suspicions were too vague, his desire for success was too ardent, for
him to lose sight of Prosper an instant.

Closely following the cashier, he seated himself in a dark corner of the
room, and, pretending to be sleepy, he fixed himself in a comfortable
position for taking a nap, gaped until his jaw-bone seemed about to be
dislocated, then closed his eyes, and kept perfectly quiet.

Prosper took a seat at the desk of an absent clerk. The others were
burning to know the result of the investigation; their eyes shone with
curiosity, but they dared not ask a question.

Unable to refrain himself any longer, little Cavaillon, Prosper's
defender, ventured to say:

"Well, who stole the money?"

Prosper shrugged his shoulders.

"Nobody knows," he replied.

Was this conscious innocence or hardened recklessness? The clerks
observed with bewildered surprise that Prosper had resu