“What is the truth of the letters?
“What did Miss Johnson see from the roof?
“What did she mean by ‘the window—the window?’
“Eh bien, let us take the second problem first as the easiest of solution. I went up with Nurse Leatheran and I stood where Miss Johnson had stood. From there she could see the courtyard and the archway and the north side of the building and two members of the staff. Had her words anything to do with either Mr. Reiter or Father Lavigny?
“Almost at once a possible explanation leaped to my brain. If a stranger came in from outside he could only do so in disguise. And there was only one person whose general appearance lent itself to such an impersonation. Father Lavigny! With a sun helmet, sun glasses, black beard and a monk’s long woollen robe, a stranger could pass in without the servants realising that a stranger had entered.
“Was that Miss Johnson’s meaning? Or had she gone further? Did she realize that Father Lavigny’s whole personality was a disguise? That he was someone other than he pretended to be?
“Knowing what I did know about Father Lavigny, I was inclined to call the mystery solved. Raoul Menier was the murderer. He had killed Mrs. Leidner to silence her before she could give him away. Now another person lets him see that she has penetrated his secret. She, too, must be removed.
“And so everything is explained! The second murder. Father Lavigny’s flight—minus robe and beard. (He and his friend are doubtless careering through Syria with excellent passports as two commercial travellers.) His action in placing the blood-stained quern under Miss Johnson’s bed.
“As I say, I was almost satisfied—but not quite. For the perfect solution must explain everything—and this does not do so.
“It does not explain, for instance, why Miss Johnson should say ‘the window,’ as she was dying. It does not explain her fit of weeping over the letter. It does not explain her mental attitude on the roof—her incredulous horror and her refusal to tell Nurse Leatheran what it was that she now suspected or knew.
“It was a solution that fitted the outer facts, but it did not satisfy the psychological requirements.
“And then, as I stood on the roof, going over in my mind those three points: the letters, the roof, the window, I saw—just as Miss Johnson had seen!
“And this time what I saw explained everything!”
Twenty-eight
JOURNEY’S END
Poirot looked round. Every eye was now fixed upon him. There had been a certain relaxation—a slackening of tension. Now the tension suddenly returned.
There was something coming . . . something . . .
Poirot’s voice, quiet and unimpassioned, went on: “The letters, the roof, ‘the window’ . . . Yes, everything was explained—everything fell into place.
“I said just now that three men had alibis for the time of the crime. Two of those alibis I have shown to be worthless. I saw now my great—my amazing mistake. The third alibi was worthless too. Not only could Dr. Leidner have committed the murder—but I was convinced that he had committed it.”
There was a silence, a bewildered, uncomprehending silence. Dr. Leidner said nothing. He seemed lost in his faraway world still. David Emmott, however, stirred uneasily and spoke.
“I don’t know what you mean to imply, M. Poirot. I told you that Dr. Leidner never left the roof until at least a quarter to three. That is the absolute truth. I swear it solemnly. I am not lying. And it would have been quite impossible for him to have done so without my seeing him.”
Poirot nodded.
“Oh, I believe you. Dr. Leidner did not leave the roof. That is an undisputed fact. But what I saw—and what Miss Johnson had seen—was that Dr. Leidner could murder his wife from the roof without leaving it.”
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.