Madame reflected, then shook her head.
"I do not think so. I am almost sure it could not. The doors were all shut."
"Could any one have been concealed in the room?"
"There is the big cupboard in the corner—but the idea is absurd."
"Pas tout à fait, madame. One thing more: did M. Halliday make any mention of his plans for the evening?"
"He said nothing whatever, monsieur."
"I thank you, madame, and I apologise for disturbing you. Pray do not trouble—we can find our way out."
We stepped out into the hall. A lady was just entering the front door as we did so. She ran quickly up the stairs, and I was left with an impression of the heavy mourning that denotes a French widow.
"A most unusual type of woman, that," remarked Poirot, as we walked away.
"Madame Olivier? Yes, she—"