“Looking at the matter psychologically, I drew one deduction which I was convinced was correct. The second ‘scandal’ she spoke of was not the same as the first—and it concerned herself!
“Let us reconstruct. At 4 o’clock, Mrs. Inglethorp quarrels with her son, and threatens to denounce him to his wife—who, by the way, overheard the greater part of the conversation. At 4:30, Mrs. Inglethorp, in consequence of a conversation on the validity of wills, makes a will in favour of her husband, which the two gardeners witness. At 5 o’clock, Dorcas finds her mistress in a state of considerable agitation, with a slip of paper—‘a letter,’ Dorcas thinks—in her hand, and it is then that she orders the fire in her room to be lighted. Presumably, then, between 4:30 and 5 o’clock, something has occurred to occasion a complete revolution of feeling, since she is now as anxious to destroy the will, as she was before to make it. What was that something?
“As far as we know, she was quite alone during that half-hour. Nobody entered or left that boudoir. What then occasioned this sudden change of sentiment?
“One can only guess, but I believe my guess to be correct. Mrs. Inglethorp had no stamps in her desk. We know this, because later she asked Dorcas to bring her some. Now in the opposite corner of the room stood her husband’s desk—locked. She was anxious to find some stamps, and, according to my theory, she tried her own keys in the desk. That one of them fitted I know. She therefore opened the desk, and in searching for the stamps she came across something else—that slip of paper which Dorcas saw in her hand, and which assuredly was never meant for Mrs. Inglethorp’s eyes. On the other hand, Mrs. Cavendish believed that the slip of paper to which her mother-in-law clung so tenaciously was a written proof of her own husband’s infidelity. She demanded it from Mrs. Inglethorp who assured her, quite truly, that it had nothing to do with that matter. Mrs. Cavendish did not believe her. She thought that Mrs. Inglethorp was shielding her stepson. Now Mrs. Cavendish is a very resolute woman, and, behind her mask of reserve, she was madly jealous of her husband. She determined to get hold of that paper at all costs, and in this resolution chance came to her aid. She happened to pick up the key of Mrs. Inglethorp’s despatch-case, which had been lost that morning. She knew that her mother-in-law invariably kept all important papers in this particular case.
“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 induced 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 cocoa which she took every night to Mrs. Inglethorp’s room. I accordingly secured a sample of that cocoa, and sent it to be analysed.”
“But that had already been done by Dr. Bauerstein,” said Lawrence quickly.
“Not exactly. The analyst was asked by him to report whether strychnine was, or was not, present. He did not have it tested, as I did, for a narcotic.”
“For a narcotic?”
“Yes. Here is the analyst’s report. Mrs. Cavendish administered a safe, but effectual, narcotic to both Mrs. Inglethorp and Mademoiselle Cynthia. And it is possible that she had a mauvais quart d’heure in consequence! Imagine her feelings when her mother-in-law is suddenly taken ill and dies, and immediately after she hears the word ‘Poison’! She has believed that the sleeping draught she administered was perfectly harmless, but there is no doubt that for one terrible moment she must have feared that Mrs. Inglethorp’s death lay at her door. She is seized with panic, and under its influence she hurries downstairs, and quickly drops the coffee-cup and saucer used by Mademoiselle Cynthia into a large brass vase,
