Poirot nodded. He said: "I noted Lady Westholme's description of your gait when you passed her. That is why I knew your wife was not speaking the truth when she said she told you after you were both back at the camp. Continue, M. Boynton."

"I hardly knew what I was doing. . . . But as I got near, my brain seemed to clear. It flashed over me that I had only myself to blame! I'd been a miserable worm! I ought to have defied my stepmother and cleared out years ago. And it came to me that it mightn't be too late even now. There she was, the old devil, sitting up like an obscene idol against the red cliffs. I went right up to have it out with her. I meant to tell her just what I thought and to announce that I was clearing out. I had a wild idea I might get away at once that evening—clear out with Nadine and get as far as Ma'an anyway that night."

"Oh, Lennox—my dear—" It was a long soft sigh.

He went on: "And then, my God—you could have struck me down with a touch! She was dead. Sitting there—dead. . . . I—I didn't know what to do. I was dumb—dazed. Everything I was going to shout out at her bottled up inside me—turning to lead—I can't explain. . . . Stone—that's what it felt like—being turned to stone. I did something mechanically. I picked up her wristwatch (it was lying in her lap) and put it around her wrist—her horrid, limp, dead wrist. . . ."

He shuddered.

"God! It was awful! Then I stumbled down, went into the marquee. I ought to have called someone, I suppose but I couldn't. I just sat there, turning the pages—waiting. . . ."

He stopped.

"You won't believe that—you can't. Why didn't I call someone? Tell Nadine? I don't know."

Dr. Gerard cleared his throat. "Your statement is perfectly plausible, M. Boynton," he said. "You were in a bad nervous condition. Two severe shocks administered in rapid succession would be quite enough to put you in the condition you have described It is the Weissenhalter reaction—best exemplified in the case of a bird that has dashed its head against a window. Even after its recovery it refrains instinctively from all action—giving itself time to readjust the nerve centers. I do not express myself well in English, but what I mean is this: You could not have acted any other way. Any decisive action of any kind would have been quite impossible for you! You passed through a period of mental paralysis."

He turned to Poirot. "I assure you, my friend, that is so!"

"Oh, I do not doubt it," said Poirot. "There was a little fact I had already noted—the fact that M. Boynton had replaced his mother's wristwatch. That was capable of two explanations—it might have been a cover for the actual deed, or it might have been observed and misinterpreted by young Mrs. Boynton. She returned only five minutes after her husband. She must therefore have seen that action. When she got up to her mother-in-law and found her dead, with the mark of a hypodermic syringe on her wrist, she would naturally jump to the conclusion that her husband had committed the deed—that her announcement of her decision to leave him had produced a reaction in him different from that for which she had hoped. Briefly. Nadine Boynton believed that she had inspired her husband to commit murder."