"You decided to leave your husband?"
"Yes."
"Continue, Madame."
Nadine said in a lower voice: "Having once made my decision I wanted to - to establish it as soon as possible.
I walked home to the camp by myself.
My mother-in-law was sitting alone, there was one about, and I decided to break the news to her right there.
I got a chair, sat down by her and told her abruptly what I had decided."
"She was surprised?"
"Yes I am afraid it was a great shock to her.
She was both surprised and angry - very angry. She - she worked herself into quite a state about it! Presently I refused to discuss the matter any longer. I got up and walked away." Her voice dropped. "I - I never saw her again alive."
Poirot nodded his head slowly.
He said: "I see."
Then he said: "You think her death was the result of the shock?"
"It seems to me almost certain.
You see, she had already overexerted herself considerably getting to this place. My news, and her anger at it, would do the rest... I feel additionally guilty because I have had a certain amount of training in illness and so I, more than anyone else, ought to have realized the possibility of such a thing happening."
Poirot sat in silence for some minutes, then he said: "What exactly did you do when you left her?"
"I took the chair I had brought out back into my cave, then I went down to the marquee.
My husband was there."
Poirot watched her closely as he said:
"Did you tell him of your decision?
Or had you already told him?"
There was a pause, an infinitesimal pause, before Nadine said:
"I told him then."
"How did he take it?"
She answered quietly: "He was very upset."
"Did he urge you to reconsider your decision?"
She shook her head.
"He - he didn't say very much.
You see, we had both known for some time that something like this might happen."
Poirot said: "You will pardon me, but the other man was, of course, M. Jefferson Cope?"
She bent her head. "Yes."
There was a long pause, then, without any change of voice, Poirot asked:
"Do you own a hypodermic syringe, Madame?"
"Yes - no."
His eyebrows rose. She explained.
"I have an old hypodermic amongst other things in a traveling medicine chest, but it is in our big luggage which we left in Jerusalem."
"I see."
There was a pause, then she said with a shiver of uneasiness: "Why did you ask me that, M. Poirot?"
He did not answer the question. Instead he put one of his own.
"Mrs. Boynton was, I believe, taking a mixture containing digitalis?"
"Yes."
He thought that she was definitely watchful now.
"That was for her heart trouble?"
"Yes."
"Digitalis is, to some extent, a cumulative drug?"
"I believe it is.
I do not know very much about it."
"Mrs. Boynton had taken a big overdose of digitalis - "
She interrupted him quickly but with decision. "She did not. She was always most careful. So was I, if I measured the dose for her."
"There might have been an overdose in this particular bottle. A mistake of the chemist who made it up?"