“It enabled me to descend from my window a couple of hours ago and to return again quite recently without disturbing the household. Don’t reproach me, Knox. I know it is a breach of confidence, but so is the behaviour of Colonel Menendez.” “You refer to his reticence on certain points?” “I do. I have a reputation to lose, Knox, and if an ingenious piece of Chinese workmanship can save it, it shall be saved.” “But, my dear Harley, why should you want to leave the house secretly at night?” Paul Harley’s cigarette glowed in the dark, then: “My original object,” he replied, “was to endeavour to learn if any one were really watching the place. For instance, I wanted to see if all lights were out at the Guest House.” “And were they?” I asked, eagerly. “They were. Secondly,” he continued, “I wanted to convince myself that there were no nocturnal prowlers from within or without.” “What do you mean by within or without?” “Listen, Knox.” He bent toward me in the dark, grasping my shoulder firmly. “One window in Cray’s Folly was lighted up.” “At what hour?” “The light is there yet.” That he was about to make some strange revelation I divined. I detected the fact, too, that he believed this revelation would be unpleasant to me; and in this I found an explanation of his earlier behaviour. He had seemed distraught and ill at ease when he had joined Madame de Stämer, Miss Beverley, and myself in the drawing room. I could only suppose that this and the abrupt parting with me outside my door had been due to his holding a theory which he had proposed to put to the test before confiding it to me. I remember that I spoke very slowly as I asked him the question: “Whose is the lighted window, Harley?” “Has Colonel Menendez taken you into a little snuggery or smoke-room which faces his bedroom in the southeast corner of the house?” “No, but Miss Beverley has mentioned the room.” “Ah. Well, there is a light in that room, Knox.” “Possibly the Colonel has not retired?” “According to Madame de Stämer he went to bed several hours ago, you may remember.” “True,” I murmured, fumbling for the significance of his words. “The next point is this,” he resumed. “You saw Madame retire to her own room, which, as you know, is on the ground floor, and I have satisfied myself that the door communicating with the servants’ wing is locked.” “I see. But to what is all this leading, Harley?” “To a very curious fact, and the fact is this: The Colonel is not alone.” I sat bolt upright. “What?” I cried. “Not so loud,” warned Harley. “But, Harley--” “My dear fellow, we must face facts. I repeat, the Colonel is not alone.” “Why do you say so?” “Twice I have seen a shadow on the blind of the smoke-room.” “His own shadow, probably.” Again Paul Harley’s cigarette glowed in the darkness. “I am prepared to swear,” he replied, “that it was the shadow of a woman.” “Harley----”