Occupied in studying the safe-lock, he manifested signs of a lively surprise.  Evidently he had just made an important discovery.

M. Fauvel, Prosper, and the commissary rose, and surrounded him.

“Have you discovered any trace?” said the banker, eagerly.

Fanferlot turned around with a vexed air.  He reproached himself for not having concealed his impressions.

“Oh!” said he, carelessly, “I have discovered nothing of importance.”

“But we should like to know,” said Prosper.

“I have merely convinced myself that this safe has been recently opened or shut, I know not which, with great violence and haste.”

“Why so?” asked the commissary, becoming attentive.

“Look, monsieur, at this scratch near the lock.”

The commissary stooped down, and carefully examined the safe; he saw a light scratch several inches long that had removed the outer coat of varnish.

“I see the scratch,” said he, “but what does that prove?”

“Oh, nothing at all!” said Fanferlot.  “I just now told you it was of no importance.”

Fanferlot said this, but it was not his real opinion.

This scratch, undeniably fresh, had for him a signification that escaped the others.  He said to himself, “This confirms my suspicions.  If the cashier had stolen millions, there was no occasion for his being in a hurry; whereas the banker, creeping down in the dead of night with cat-like footsteps, for 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.