“Have pity on me, monsieur!” She looked up at me through her tears, and the pose was distinctly effective.  “It was Madame Deschamps who asked me to do it.  I used to be with her before I came to mademoiselle.  She gave me the bottle, but I didn’t know it was poison—­I swear I didn’t!”

“What did you take it to be, then?  Jam?  Two grains of atropine will cause death.”

For answer she clung to my knees.  I released myself, and moved away a few steps.  She jumped up, and made a dash for the door, but I happened to have locked it.

“Where is Madame Deschamps?” I asked.

“She returns to Paris to-morrow.  Monsieur will let me go.  I was only a tool.”

“I will consider that matter, Yvette,” I said.  “In my opinion you are a thoroughly wicked girl, and I wouldn’t trust you any further than I could see you.  For the present, you will have an opportunity to meditate over your misdoings.”  I left the room, and locked the door on the outside.

Impossible to disguise the fact that I was enormously pleased with myself—­with my sharpness, my smartness, my penetration, my success.

CHAPTER XIII

THE PORTRAIT

For the next hour or two I wandered about Rosa’s flat like an irresolute and bewildered spirit.  I wished to act, yet without Rosa I scarcely liked to do so.  That some sort of a plot existed—­whether serious or trivial was no matter—­there could be little doubt, and there could be little doubt also that Carlotta Deschamps was at the root of it.

Several half-formed schemes flitted through my head, but none of them seemed to be sufficiently clever.  I had the idea of going to see Carlotta Deschamps in order to warn her.  Then I thought the warning might perhaps be sent through her sister Marie, who was doubtless in Paris, and who would probably be able to control Carlotta.  I had not got Carlotta’s address, but I might get it by going to the Casino de Paris, and asking Marie for it.  Perhaps Marie, suspicious, might refuse the address.  Had she not said that she and Carlotta were as thick as thieves?  Moreover, assuming that I could see Carlotta, what should I say to her?  How should I begin?  Then it occurred to me that the shortest way with such an affair was to go directly to the police, as I had already threatened Yvette; but the appearance of the police would mean publicity, scandal, and other things unpleasant for Rosa.  So it fell out that I maintained a discreet inactivity.

Towards nightfall I went into the street to breathe the fresh air.  A man was patrolling the pavement in a somewhat peculiar manner.  I returned indoors, and after half an hour reconnoitred once more.  The man was on the opposite side of the road, with his eyes on the windows of the salon.  When he caught sight of me he walked slowly away.  He might have been signalling to Yvette, who was still under lock and key, but this possibility did not disturb me, as escape was out of the question for her.