“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.”