“Monsieur Job—­ “Get together six or eight of our men at once and take them to the wine merchant’s at the corner of the Rue des Martyrs and the Rue Lamartine; await my orders there.”

“Why there and not here?”

“Because we must avoid needless excursions.  At the place I have designated we are only two steps from Madame Charman’s and near Tremorel’s retreat; for the wretch has hired his rooms in the quarter of Notre Dame de Lorette.”

M. Plantat gave an exclamation of surprise.

“What makes you think that?”

The detective smiled, as if the question seemed foolish to him.

“Don’t you recollect that the envelope of the letter addressed by Mademoiselle Courtois to her family to announce her suicide bore the Paris postmark, and that of the branch office of Rue St. Lazare?  Now listen to this:  On leaving her aunt’s house, Laurence must have gone directly to Tremorel’s apartments, the address of which he had given her, and where he had promised to meet her on Thursday morning.  She wrote the letter, then, in his apartments.  Can we admit that she had the presence of mind to post the letter in another quarter than that in which she was?  It is at least probable that she was ignorant of the terrible reasons which Tremorel had to fear a search and pursuit.  Had Hector foresight enough to suggest this trick to her?  No, for if he wasn’t a fool he would have told her to post the letter somewhere outside of Paris.  It is therefore scarcely possible that it was posted anywhere else than at the nearest branch office.”

These suppositions were so simple that M. Plantat wondered he had not thought of them before.  But men do not see clearly in affairs in which they are deeply interested; passion dims the eyes, as heat in a room dims a pair of spectacles.  He had lost, with his coolness, a part of his clearsightedness.  His anxiety was very great; for he thought M. Lecoq had a singular mode of keeping his promise.

“It seems to me,” he could not help remarking, “that if you wish to keep Hector from trial, the men you have summoned together will be more embarrassing than useful.”

M. Lecoq thought that his guest’s tone and look betrayed a certain doubt, and was irritated by it.

“Do you distrust me, Monsieur Plantat?”

The old man tried to protest.

“Believe me—­”

“You have my word,” resumed M. Lecoq, “and if you knew me better you would know that I always keep it when I have given it.  I have told you that I would do my best to save Mademoiselle Laurence; but remember that I have promised you my assistance, not absolute success.  Let me, then, take such measures as I think best.”

So saying, he rang for Janouille.

“Here’s a letter,” said he when she appeared, “which must be sent to Job at once.”

“I will carry it.”

“By no means.  You will be pleased to remain here and wait for the men that I sent out this morning.  As they come in, send them to the wine merchant’s at the corner of the Rue des Martyrs; you know it—­opposite the church.  They’ll find a numerous company there.”