Poirot sat down and drew out his case of tiny Russian cigarettes. He smoked for a minute or two in silence. Then:
“Use your little grey cells,” he said. “There is always a reason behind my actions.”
I hesitated for a moment, and then I said slowly:
“The first one that occurs to me is that you yourself do not know who the guilty person is, but that you are sure that he is to be found amongst the people here tonight. Therefore your words were intended to force a confession from the unknown murderer?”
Poirot nodded approvingly. “A clever idea, but not the truth.”
“I thought, perhaps, that by making him believe you knew, you might force him out into the open—not necessarily by confession. He might try to silence you as he formerly silenced Mr. Ackroyd—before you could act tomorrow morning.”
“A trap with myself as the bait! Merci, mon ami, but I am not sufficiently heroic for that.”
“Then I fail to understand you. Surely you are running the risk of letting the murderer escape by thus putting him on his guard?”
Poirot shook his head. “He cannot escape,” he said gravely. “There is only one way out—and that way does not lead to freedom.”
“You really believe that one of those people here tonight committed the murder?” I asked incredulously.
“Yes, my friend.”
“Which one?”
There was a silence for some minutes. Then Poirot tossed the stump of his cigarette into the grate and began to speak in a quiet, reflective tone.
“I will take you the way that I have travelled myself. Step by step you shall accompany me, and see for yourself that all the facts point indisputably to one person. Now, to begin with, there were two facts and one little discrepancy in time which especially attracted my attention. The first fact was the telephone call. If Ralph Paton were indeed the murderer, the telephone call became meaningless and absurd. Therefore, I said to myself, Ralph Paton is not the murderer.
“I satisfied myself that the call could not have been sent by anyone in the house, yet I was convinced that it was amongst those present on the fatal evening that I had to look for my criminal. Therefore I concluded that the telephone call must have been sent by an accomplice. I was not quite pleased with that deduction, but I let it stand for the minute.
“I next examined the motive for the call. That was difficult. I could only get at it by judging its result. Which was—that the murder was discovered that night instead of—in all probability—the following morning. You agree with that?”
“Ye‑es,” I admitted. “Yes. As you say, Mr. Ackroyd, having given orders that he was not to be disturbed, nobody would have been likely to go to the study that night.”
“Très bien. The affair marches, does it not? But matters were still obscure. What was the advantage of having the crime discovered that night in preference to the following morning? The only idea I could get hold of was that the murderer, knowing the crime was to be discovered at a certain time, could make sure of being present when the door was broken in—or at any rate immediately afterwards. And now we come to the second fact—the chair pulled out from the wall. Inspector Raglan dismissed that as of no importance. I, on the contrary, have always regarded it as of supreme importance.
“In your manuscript you have drawn a neat little plan of the study. If you had it with you this minute you would see that—the chair being drawn out in the position indicated by Parker—it would stand in a direct line between the door and the window.”
“The window!” I said quickly.
“You, too, have my first idea. I imagined that the chair was drawn out so that something connected with the window should not be seen by anyone entering through the door. But I soon abandoned that supposition, for though the chair was a grandfather with a high back, it obscured very little of the window—only the part between the sash and the ground. No, mon ami—but remember that just in front of the window there stood a table with books and magazines upon it. Now that table was completely hidden by the drawn-out chair—and immediately I had my first shadowy suspicion of the truth.
“Supposing that there had been something on that table not intended to be seen? Something placed there by the murderer? As yet I had no inkling of what that something might be. But I knew certain very interesting facts about it. For instance, it was something that the murderer had not been able to take away with him at the time that he committed the crime. At the same time it was vital that it should be removed as soon as possible after the crime had been discovered. And so—the telephone message, and the opportunity for the murderer to be on the spot when the body was discovered.
“Now four people were on the scene before the police arrived. Yourself, Parker, Major Blunt, and Mr. Raymond. Parker I eliminated at once, since at whatever time the crime was discovered, he was the one person certain to be on the spot. Also it was he who told me of the pulled-out chair. Parker, then, was cleared (of the murder, that is. I still thought it possible that he had been blackmailing Mrs. Ferrars). Raymond and Blunt, however, remained under suspicion since, if the crime had been discovered in the early hours of the morning, it was quite possible that they might have arrived on the scene too late to prevent the object on the round table being discovered.
“Now what was that object? You heard my arguments tonight in reference to the scrap of conversation overheard? As soon as I learned that a representative of a dictaphone company had called, the idea of a dictaphone took root in my mind. You heard what I said in this room not half an hour
