“M.  Fanferlot,” he said, “go and see if you cannot discover some traces that may have escaped the attention of these gentlemen.”

M. Fanferlot, nicknamed the Squirrel, was indebted to his prodigious agility for this title, of which he was not a little proud.  Slim and insignificant in appearance he might, in spite of his iron muscles, be taken for a bailiff’s under clerk, as he walked along buttoned up to the chin in his thin black overcoat.  He had one of those faces that impress us disagreeably—­an odiously turned-up nose, thin lips, and little, restless black eyes.

Fanferlot, who had been on the police force for five years, burned to distinguish himself, to make for himself a name.  He was ambitious.  Alas! he was unsuccessful, lacking opportunity—­or genius.

Already, before the commissary spoke to him, he had ferreted everywhere; studied the doors, sounded the partitions, examined the wicket, and stirred up the ashes in the fireplace.

“I cannot imagine,” said he, “how a stranger could have effected an entrance here.”

He walked around the office.

“Is this door closed at night?” he inquired.

“It is always locked.”

“And who keeps the key?”

“The office-boy, to whom I always give it in charge before leaving the bank,” said Prosper.

“This boy,” said M. Fauvel, “sleeps in the outer room on a sofa-bedstead, which he unfolds at night, and folds up in the morning.”

“Is he here now?” inquired the commissary.

“Yes, monsieur,” answered the banker.

He opened the door and called: 

“Anselme!”

This boy was the favorite servant of M. Fauvel, and had lived with him for ten years.  He knew that he would not be suspected; but the idea of being connected in any way with a robbery is terrible, and he entered the room trembling like a leaf.

“Did you sleep in the next room last night?” asked the commissary.

“Yes, monsieur, as usual.”

“At what hour did you go to bed?”

“About half-past ten; I had spent the evening at a cafe near by, with monsieur’s valet.”

“Did you hear no noise during the night?”

“Not a sound; and still I sleep so lightly, that, if monsieur comes down to the cash-room when I am asleep, I am instantly awakened by the sound of his footsteps.”

“Monsieur Fauvel often comes to the cash-room at night, does he?”

“No, monsieur; very seldom.”

“Did he come last night?”

“No, monsieur, I am very certain he did not; for I was kept awake nearly all night by the strong coffee I had drunk with the valet.”

“That will do; you can retire,” said the commissary.

When Anselme had left the room, Fanferlot resumed his search.  He opened the door of the private staircase.

“Where do these stairs lead to?” he asked.

“To my private office,” replied M. Fauvel.