“Of all the servants of the chateau,” remarked M. Plantat, “there remains not one who knew Sauvresy.  The domestics have one by one been replaced.”

“No doubt,” answered the doctor, “the sight of the old servants would be disagreeable to Monsieur de Tremorel.”

He was interrupted by the mayor, who re-entered, his eyes glowing, his face animated, wiping his forehead.

“I have let the people know,” said he, “the indecency of their curiosity.  They have all gone away.  They were anxious to get at Philippe Bertaud, the brigadier says; public opinion has a sharp scent.”

Hearing the door open, he turned, and found himself face to face with a man whose features were scarcely visible, so profoundly did he bow, his hat pressed against his breast.

“What do you wish?” sternly asked M. Courtois.  “By what right have you come in here?—­Who are you?”

The man drew himself up.

“I am Monsieur Lecoq,” he replied, with a gracious smile.  “Monsieur Lecoq of the detective force, sent by the prefect of police in reply to a telegram, for this affair.”

This declaration clearly surprised all present, even the judge of instruction.

In France, each profession has its special externals, as it were, insignia, which betray it at first view.  Each profession has its conventional type, and when public opinion has adopted a type, it does not admit it possible that the type should be departed from.  What is a doctor?  A grave man, all in black, with a white cravat.  A gentleman with a capacious stomach, adorned with heavy gold seals, can only be a banker.  Everybody knows that the artist is a merry liver, with a peaked hat, a velvet vest, and enormous ruffles.  By virtue of this rule, the detective of the prefecture ought to have an eye full of mystery, something suspicious about him, a negligence of dress, and imitation jewelry.  The most obtuse shopkeeper is sure that he can scent a detective at twenty paces a big man with mustaches, and a shining felt hat, his throat imprisoned by a collar of hair, dressed in a black, threadbare surtout, carefully buttoned up on account of the entire absence of linen.  Such is the type.  But, according to this, M. Lecoq, as he entered the dining-room at Valfeuillu, had by no means the air of a detective.  True, M. Lecoq can assume whatever air he pleases.  His friends declare that he has a physiognomy peculiar to himself, which he resumes when he enters his own house, and which he retains by his own fireside, with his slippers on; but the fact is not well proved.  What is certain, is that his mobile face lends itself to strange metamorphoses; that he moulds his features according to his will, as the sculptor moulds clay for modelling.  He changes everything, even his look.

“So,” said the judge of instruction, “the prefect has sent you to me, in case certain investigations become necessary.”

“Yes, Monsieur, quite at your service.”