“Excuse me, you had taken egg-and-milk.  Here is the glass out of which you drank it.”  I picked up the glass, which had been left on the table, and which still contained about a spoonful of egg-and-milk.

Yvette entered in response to my summons.

“Mademoiselle has returned soon,” the girl began lightly.

“Yes.”

The two women looked at each other.  I hastened to the door, and held it open for Rosa to pass out.  She did so.  I closed the door, and put my back against it.  The glass I still held in my hand.

“Now, Yvette, I want to ask you a few questions.”

She stood before me, pretty even in her plain black frock and black apron, and folded her hands.  Her face showed no emotion whatever.

“Yes, monsieur, but mademoiselle will need me.”

“Mademoiselle will not need you.  She will never need you again.”

“Monsieur says?”

“You see this glass.  What did you put in it?”

“The cook put egg-and-milk into it.”

“I ask what you put in it?”

“I, monsieur?  Nothing.”

“You are lying, my girl.  Your mistress has been poisoned.”

“I swear—­”

“I should advise you not to swear.  You have twice attempted to poison your mistress.  Why did you do it?”

“But this is absurd.”

“Does your mistress use eyedrops when she sings at the Opera?”

“Eyedrops?”

“You know what I mean.  A lotion which you drop into the eye in order to dilate the pupil.”

“My mistress never uses eyedrops.”

“Does Madame Carlotta Deschamps use eyedrops?”

It was a courageous move on my part, but it had its effect.  She was startled.

“I—­I don’t know, monsieur.”

“I ask because eyedrops contain atropine, and mademoiselle is suffering from a slight, a very slight, attack of atropine poisoning.  The dose must have been very nicely gauged; it was just enough to produce a temporary hoarseness and discomfort.  I needn’t tell such a clever girl as you that atropine acts first on the throat.  It has clearly been some one’s intention to prevent mademoiselle from singing at rehearsals, and from appearing in Paris in ‘Carmen.’”

Yvette drew herself up, her nostrils quivering.  She had turned decidedly pale.

“Monsieur insults me by his suspicions.  I must go.”

“You won’t go just immediately.  I may tell you further that I have analyzed the contents of this glass, and have found traces of atropine.”

I had done no such thing, but that was a detail.

“Also, I have sent for the police.”

This, too, was an imaginative statement.

Yvette approached me suddenly, and flung her arms round my neck.  I had just time to put the glass on the seat of a chair and seize her hands.

“No,” I said, “you will neither spill that glass nor break it.”

She dropped at my feet weeping.