He spoke so gravely, and with such assurance, that I could not fail to be convinced. But I essayed one final objection: “And the match and cigarette end found near the body? What of them.” A light of pure enjoyment lit up Poirot’s face. “Planted! Deliberately planted there for Giraud or one of his tribe to find! Ah, he is smart, Giraud, he can do his tricks! So can a good retriever dog. He comes in so pleased with himself. For hours he has crawled on his stomach. ‘See what I have found,’ he says. And then again to me: ‘What do you see here?’ Me, I answer, with profound and deep truth, ‘Nothing.’ And Giraud, the great Giraud, he laughs, he thinks to himself, ‘Oh, that he is imbecile, this old one!’ _But we shall see.…___” But my mind had reverted to the main facts. “Then all this story of the masked men—?” “Is false.” “What really happened?” Poirot shrugged his shoulders. “One person could tell us—Madame Renauld. But she will not speak. Threats and entreaties would not move her. A remarkable woman that, Hastings. I recognized as soon as I saw her that I had to deal with a woman of unusual character. At first, as I told you, I was inclined to suspect her of being concerned in the crime. Afterwards I altered my opinion.” “What made you do that?” “Her spontaneous and genuine grief at the sight of her husband’s body. I could swear that the agony in that cry of hers was genuine.” “Yes,” I said thoughtfully, “one cannot mistake these things.” “I beg your pardon, my friend—one can always be mistaken. Regard a great actress, does not her acting of grief carry you away and impress you with its reality? No, however strong my own impression and belief, I needed other evidence before I allowed myself to be satisfied. The great criminal can be a great actor. I base my certainty in this case, not upon my own impression, but upon the undeniable fact that Mrs. Renauld actually fainted. I turned up her eyelids and felt her pulse. There was no deception—the swoon was genuine. Therefore I was satisfied that her anguish was real and not assumed. Besides, a small additional point not without interest, it was unnecessary for Mrs. Renauld to exhibit unrestrained grief. She had had one paroxysm on learning of her husband’s death, and there would be no need for her to simulate another such a violent one on beholding his body. No, Mrs. Renauld was not her husband’s murderess. But why has she lied? She lied about the wrist watch, she lied about the masked men—she lied about a third thing. Tell me, Hastings, what is your explanation of the open door?” “Well,” I said, rather embarrassed, “I suppose it was an oversight. They forgot to shut it.” Poirot shook his head, and sighed. “That is the explanation of Giraud. It does not satisfy me. There is a meaning behind that open door which for a moment I cannot fathom.” “I have an idea,” I cried suddenly. “_A la bonne heure!___ Let us hear it.”