This was a formal dismissal; and M. Verduret, understanding it thus, bowed to M. Fauvel, and left the room, accompanied by Prosper, who had not opened his lips.

They had reached the street before Prosper recovered the use of his tongue.

“I hope you are satisfied, monsieur,” he said, in a gloomy tone; “you exacted this painful step, and I could only acquiesce.  Have I gained anything by adding this humiliation to the others which I have suffered?”

“You have not, but I have,” replied M. Verduret.  “I could find no way of gaining access to M. Fauvel, save through you; and now I have found out what I wanted to know.  I am convinced that M. Fauvel had nothing to do with the robbery.”

“Oh, monsieur!” objected Prosper, “innocence can be feigned.”

“Certainly, but not to this extent.  And this is not all.  I wished to find out if M. Fauvel would be accessible to certain suspicions.  I am now confident that he is.”

Prosper and his companion had stopped to talk more at their ease, near the corner of the Rue Lafitte, in the middle of a large space which had lately been cleared by pulling down an old house.

M. Verduret seemed to be anxious, and was constantly looking around as if he expected someone.

He soon uttered an exclamation of satisfaction.

At the other end of the vacant space, he saw Cavaillon, who was bareheaded and running.

He was so excited that he did not even stop to shake hands with Prosper, but darted up to M. Verduret, and said: 

“They have gone, monsieur!”

“How long since?”

“They went about a quarter of an hour ago.”

“The deuce they did!  Then we have not an instant to lose.”

He handed Cavaillon the note he had written some hours before at Prosper’s house.

“Here, send him this, and then return at once to your desk; you might be missed.  It was very imprudent in you to come out without your hat.”

Cavaillon ran off as quickly as he had come.  Prosper was stupefied.

“What!” he exclaimed.  “You know Cavaillon?”

“So it seems,” answered M. Verduret with a smile, “but we have no time to talk; come on, hurry!”

“Where are we gong now?”

“You will soon know; walk fast!”

And he set the example by striding rapidly toward the Rue Lafayette.  As they went along he continued talking more to himself than to Prosper.

“Ah,” said he, “it is not by putting both feet in one shoe, that one wins a race.  The track once found, we should never rest an instant.  When the savage discovers the footprints of an enemy, he follows it persistently, knowing that falling rain or a gust of wind may efface the footprints at any moment.  It is the same with us:  the most trifling incident may destroy the traces we are following up.”

M. Verduret suddenly stopped before a door bearing the number 81.