“Listen. We are agreed that Mrs. Renauld’s story is a fabrication. Is it not possible, then, that Mr. Renauld left the house to keep an appointment—possibly with the murderer—leaving the front door open for his return. But he did not return, and the next morning he is found, stabbed in the back.” “An admirable theory, Hastings, but for two facts which you have characteristically overlooked. In the first place, who gagged and bound Madame Renauld? And why on earth should they return to the house to do so? In the second place, no man on earth would go out to keep an appointment wearing his underclothes and an overcoat. There are circumstances in which a man might wear pajamas and an overcoat—but the other, never!” “True,” I said, rather crest-fallen. “No,” continued Poirot, “we must look elsewhere for a solution of the open door mystery. One thing I am fairly sure of—they did not leave through the door. They left by the window.” “What?” “Precisely.” “But there were no footmarks in the flower bed underneath.” “No—_and there ought to have been.___ Listen, Hastings. The gardener, Auguste, as you heard him say, planted both those beds the preceding afternoon. In the one there are plentiful impressions of his big hobnailed boots—in the other, _none!___ You see? Some one had passed that way, some one who, to obliterate their footprints, smoothed over the surface of the bed with a rake.” “Where did they get a rake?” “Where they got the spade and the gardening gloves,” said Poirot impatiently. “There is no difficulty about that.” “What makes you think that they left that way, though? Surely it is more probable that they entered by the window, and left by the door.” “That is possible of course. Yet I have a strong idea that they left by the window.” “I think you are wrong.” “Perhaps, _mon ami___.” I mused, thinking over the new field of conjecture that Poirot’s deductions had opened up to me. I recalled my wonder at his cryptic allusions to the flower bed and the wrist watch. His remarks had seemed so meaningless at the moment and now, for the first time, I realized how remarkably, from a few slight incidents, he had unravelled much of the mystery that surrounded the case. I paid a belated homage to my friend. As though he read my thoughts, he nodded sagely. “Method, you comprehend! Method! Arrange your facts. Arrange your ideas. And if some little fact will not fit in—do not reject it but consider it closely. Though its significance escapes you, be sure that it is significant.” “In the meantime,” I said, considering, “although we know a great deal more than we did, we are no nearer to solving the mystery of who killed Mr. Renauld.” “No,” said Poirot cheerfully. “In fact we are a great deal further off.” The fact seemed to afford him such peculiar satisfaction that I gazed at him in wonder. He met my eye and smiled.