Raymond said: ‘I don’t understand.’
Carol said: ‘No more do I.’
Poirot looked from one to the other of them.
‘You do not, eh? “A servant was sent”—why a servant? Were you not, all of you, most assiduous in your attendance on the old lady as a general rule? Did not one or other of you always escort her to meals? She was infirm. It was difficult for her to rise from a chair without assistance. Always one or other of you was at her elbow. I suggest then, that on dinner being announced the natural thing would have been for one or other of her family to go out and help her. But not one of you offered to do so. You all sat there, paralyzed, watching each other, wondering, perhaps, why no one went.’
Nadine said sharply: ‘All this is absurd, M. Poirot! We were all tired that evening. We ought to have gone, I admit, but—on that evening—we just didn’t!’
‘Precisely—precisely—on that particular evening! You, madame, did perhaps more waiting on her than anyone else. It was one of the duties that you accepted mechanically. But that evening you did not offer to go out to help her in. Why? That is what I asked myself—why? And I tell you my answer. Because you knew quite well that she was dead…
‘No, no, do not interrupt me, madame.’ He raised an impassioned hand. ‘You will now listen to me—Hercule Poirot! There were witnesses to your conversation with your mother-in-law. Witnesses who could see but could not hear! Lady Westholme and Miss Pierce were a long way away. They saw you apparently having a conversation with your mother-in-law, but what actual evidence is there of what occurred? I will propound to you instead a little theory. You have brains, madame. If in your quiet unhurried fashion you have decided on—shall we say the elimination of your husband’s mother—you will carry it out with intelligence and with due preparation. You have access to Dr Gerard’s tent during his absence on the morning excursion. You are fairly sure that you will find a suitable drug. Your nursing training helps you there. You choose digitoxin—the same kind of drug that the old lady is taking—you also take his hypodermic syringe since, to your annoyance, your own has disappeared. You hope to replace the syringe before the doctor notices its absence.’
‘Before proceeding to carry out your plan, you make one last attempt to stir your husband into action. You tell him of your intention to marry Jefferson Cope. Though your husband is terribly upset he does not react as you had hoped—so you are forced to put your plan of murder into action. You return to the camp exchanging a pleasant natural word with Lady Westholme and Miss Pierce as you pass. You go up to where your mother-in-law is sitting. You have the syringe with the drug in it ready. It is easy to seize her wrist and—proficient as you are with your nurse’s training—force home the plunger. It is done before your mother-in-law realizes what you are doing. From far down the valley the others only see you talking to her, bending over her. Then deliberately you go and fetch a chair and sit there apparently engaged in an amicable conversation for some minutes. Death must have been almost instantaneous. It is a dead woman to whom you sit talking, but who shall guess that? Then you put away the chair and go down to the marquee, where you find your husband reading a book. And you are careful not to leave that marquee! Mrs Boynton’s death, you are sure, will be put down to heart trouble. (It will, indeed, be due to heart trouble.) In only one thing have your plans gone astray. You cannot return the syringe to Dr Gerard’s tent because the doctor is in there shivering with malaria—and although you do not know it, he has already missed the syringe. That, madame, was the flaw in an otherwise perfect crime.’
There was silence—a moment’s dead silence—then Lennox Boynton sprang to his feet.
‘No,’ he shouted. ‘That’s a damned lie. Nadine did nothing. She couldn’t have done anything. My mother—my mother was already dead.’
‘Ah?’ Poirot’s eyes came gently round to him. ‘So, after all, it was you who killed her, Mr Boynton.’
Again a moment’s pause—then Lennox dropped back into his chair and raised trembling hands to his face.
‘Yes—that’s right—I killed her.’
‘You took the digitoxin from Dr Gerard’s tent?’
‘Yes.’
‘When?’
‘As—as—you said—in the morning.’
‘And the syringe?’
‘The syringe? Yes.’
‘Why did you kill her?’
‘Can you ask?’
‘I am asking, Mr Boynton!’
‘But you know—my wife was leaving me—with Cope—’
‘Yes, but you only learnt that in the afternoon.’
Lenn
ox stared at him. ‘Of course. When we were out—’
‘But you took the poison and the syringe in the morning—before you knew?’
‘Why the hell do you badger me with questions?’ He paused and passed a shaking hand across his forehead. ‘What does it matter, anyway?’
‘It matters a great deal. I advise you, Mr Lennox Boynton, to tell me the truth.’
‘The truth?’ Lennox stared at him.