"Mrs. Cavendish, therefore, made her plans as only a woman driven desperate through jealousy could have done. Some time in the evening she unbolted the door leading into Mademoiselle Cynthia's room. Possibly she applied oil to the hinges, for I found that it opened quite noiselessly when I tried it. She put off her project until the early hours of the morning as being safer, since the servants were accustomed to hearing her move about her room at that time. She dressed completely in her land kit, and made her way quietly through Mademoiselle Cynthia's room into that of Mrs. Inglethorp."
He paused a moment, and Cynthia interrupted: "But I should have woken up if anyone had come through my room?"
"Not if you were drugged, mademoiselle."
"Drugged?"
"Mais, oui!"
"You remember"--he addressed us collectively again--"that through all the tumult and noise next door Mademoiselle Cynthia slept. That admitted of two possibilities. Either her sleep was feigned--which I did not believe--or her unconsciousness was indeed by artificial means.
"With this latter idea in my mind, I examined all the coffee-cups most carefully, remembering that it was Mrs. Cavendish who had brought Mademoiselle Cynthia her coffee the night before. I took a sample from each cup, and had them analysed--with no result. I had counted the cups carefully, in the event of one having been removed. Six persons had taken coffee, and six cups were duly found. I had to confess myself mistaken.
"Then I discovered that I had been guilty of a very grave oversight. Coffee had been brought in for seven persons, not six, for Dr. Bauerstein had been there that evening. This changed the face of the whole affair, for there was now one cup missing. The servants noticed nothing, since Annie, the housemaid, who took in the coffee, brought in seven cups, not knowing that Mr. Inglethorp never drank it, whereas Dorcas, who cleared them away the following morning, found six as usual--or strictly speaking she found five, the sixth being the one found broken in Mrs. Inglethorp's room.
"I was confident that the missing cup was that of Mademoiselle Cynthia. I had an additional reason for that belief in the fact that all the cups found contained sugar, which Mademoiselle Cynthia never took in her coffee. My attention was attracted by the story of Annie about some 'salt' on the tray of coco which she took every night to Mrs. Inglethorp's room. I accordingly secured a sample of that coco, and sent it to be analysed."