We all stared.
‘The window,’ cried Poirot. ‘Her window! That is what I realized – just as Miss Johnson realized it. Her window was directly underneath, on the side away from the courtyard. And Dr Leidner was alone up there with no one to witness his actions. And those heavy stone querns and grinders were up there all ready to his hand. So simple, so very simple, granted one thing – that the murderer had the opportunity to move the body before anyone else saw it… Oh, it is beautiful – of an unbelievable simplicity!
‘Listen – it went like this:
‘Dr Leidner is on the roof working with the pottery. He calls you up, Mr Emmott, and while he holds you in talk he notices that, as usually happens, the small boy takes advantage of your absence to leave his work and go outside the courtyard. He keeps you with him ten minutes, then he lets you go and as soon as you are down below shouting to the boy he sets his plan in operation.
‘He takes from his pocket the plasticine-smeared mask with which he has already scared his wife on a former occasion and dangles it over the edge of the parapet till it taps on his wife’s window.
‘That, remember, is the window giving on the countryside facing the opposite direction to the courtyard.
‘Mrs Leidner is lying on her bed half asleep. She is peaceful and happy. Suddenly the mask begins tapping on the window and attracts her attention. But it is not dusk now – it is broad daylight – there is nothing terrifying about it. She recognizes it for what it is – a crude form of trickery! She is not frightened but indignant. She does what any other woman would do in her place. Jumps off the bed, opens the window, passes her head through the bars and turns her face upward to see who is playing the trick on her.
‘Dr Leidner is waiting. He has in his hands, poised and ready, a heavy quern. At the psychological moment he drops it…
‘With a faint cry (heard by Miss Johnson) Mrs Leidner collapses on the rug underneath the window.
‘Now there is a hole in this quern, and through that Dr Leidner had previously passed a cord. He has now only to haul in the cord and bring up the quern. He replaces the latter neatly, bloodstained side down, amongst the other objects of that kind on the roof.
‘Then he continues his work for an hour or more till he judges the moment has come for the second act. He descends the stairs, speaks to Mr Emmott and Nurse Leatheran, crosses the courtyard and enters his wife’s room. This is the explanation he himself gives of his movements there:
‘“I saw my wife’s body in a heap by the bed. For a moment or two I felt paralysed as though I couldn’t move. Then at last I went and knelt down by her and lifted up her head. I saw she was dead…At last I got up. I felt dazed and as though I were drunk. I managed to get to the door and call out.”
‘A perfectly possible account of the actions of a grief-dazed man. Now listen to what I believe to be the truth. Dr Leidner enters the room, hurries to the window, and, having pulled on a pair of gloves, closes and fastens it, then picks up his wife’s body and transports it to a position between the bed and the door. Then he notices a slight stain on the window-side rug. He cannot change it with the other rug, they are a different size, but he does the next best thing. He puts the stained rug in front of the washstand and the rug from the washstand under the window. If the stain is noticed, it will be connected with the washstand – not with the window – a very important point. There must be no suggestion that the window played any part in the business. Then he comes to the door and acts the part of the overcome husband, and that, I imagine, is not difficult. For he did love his wife.’
‘My good man,’ cried Dr Reilly impatiently, ‘if he loved her, why did he kill her? Where’s the motive? Can’t you speak, Leidner? Tell him he’s mad.’
Dr Leidner neither spoke nor moved.
Poirot said: ‘Did I not tell you all along that this was a crime passionnel? Why did her first husband, Frederick Bosner, threaten to kill her? Because he loved her…And in the end, you see, he made his boast good…
‘Mais oui – mais oui – once I realize that it is Dr Leidner who did the killing, everything falls into place…
‘For the second time, I recommence my journey from the beginning – Mrs Leidner’s first marriage – the threatening letters – her second marriage. The letters prevented her marrying any other man – but they did not prevent her marrying Dr Leidner. How simple that is – if Dr Leidner is actually Frederick Bosner.
‘Once more let us start our journey – from the point of view this time of young Frederick Bosner.
‘To begin with, he loves his wife Louise with an overpowering passion such as only a woman of her kind can evoke. She betrays him. He is sentenced to death. He escapes. He is involved in a railway accident but he manages to emerge with a second personality – that of a young Swedish archaeologist, Eric Leidner, whose body is badly disfigured and who will be conveniently buried as Frederick Bosner.
‘What is the new Eric Leidner’s attitude to the woman who was willing to send him to his death? First and most important, he still loves her. He sets to work to build up his new life. He is a man of great ability, his profession is congenial to him and he makes a success of it. But he never forgets the ruling passion of his life. He keeps himself informed of his wife’s movements. Of one thing he is cold-bloodedly determined (remember Mrs Leidner’s own description of him to Nurse Leatheran – gentle and kind but ruthless), she shall belong to no other man. Whenever he judges it necessary he despatches a letter. He imitates some of the peculiarities of her handwriting in case she should think of taking his letters to the police. Women who write sensational anonymous letters to themselves are such a common phenomenon that the police will be sure to jump to that solution given the likeness of the handwriting. At the same time he leaves her in doubt as to whether he is really alive or not.
‘At last, after many years, he judges that the time has arrived; he re-enters her life. All goes well. His wife never dreams of his real identity. He is a well-known man. The upstanding, good-looking young fellow is now a middle-aged man with a beard and stooping shoulders. And so we see history repeating itself. As before, Frederick is able to dominate Louise. For the second time she consents to marry him. And no letter comes to forbid the banns.
‘But afterwards a letter does come. Why?
‘I think that Dr Leidner was taking no chances. The intimacy of marriage might awaken a memory. He wishes to impress on his wife, once and for all, that Eric Leidner and Frederick Bosner are two different people. So much so that a threatening letter comes from the former on account of the latter. The rather puerile gas poisoning business follows – arranged by Dr Leidner, of course. Still with the same object in view.
‘After that he is satisfied. No more letters need come. They can settle down to happy married life together.
‘And then, after nearly two years,the letters recommence.
‘Why? Eh bien, I think I know. Because the threat underlying the letters was always a genuine threat. (That is why Mrs Leidner has always been frightened. She knew her Frederick’s gentle but ruthless nature.) If she belongs to any other man but him he would kill her. And she has given herself to Richard Carey.
‘And so, having discovered this, cold-bloodedly, calmly, Dr Leidner prepares the scene for murder.
‘You see now the important part played by Nurse Leatheran? Dr Leidner’s rather curious conduct (it puzzled me at the very first) in securing her services for his wife is explained. It was vital that a reliable professional witness should be able to state incontrovertibly that Mrs Leidner had been dead over an hour when her body was found – that is, that she had been killed at a time when everybody could swear her husband was on the roof. A suspicion might have arisen that he had killed her when he entered the room and found the body – but that was out of the question when a trained hospital nurse would assert positively that she had already been dead an hour.