A narcotic taken with strychnine will delay the action of the poison for some hours.”
Poirot paused. Mary looked up at him, the colour slowly rising in her face.
“All you have said is quite true, Monsieur Poirot. It was the most awful hour of my life. I shall never forget it. But you are wonderful. I understand now–-”
“What I meant when I told you that you could safely confess to Papa Poirot, eh? But you would not trust me.”
“I see everything now,” said Lawrence. “The drugged coco, taken on
said Poirot unexpectedly, “we can. One of my first actions was to ring up the hospital where she was working.”
“Well?”
“Well, I learnt that Miss Howard had been on afternoon duty on Tuesday, and that—a convoy coming in unexpectedly—she had kindly offered to remain on night duty, which offer was gratefully accepted. That disposes of that.”