Save that the bed was disordered, showing that West had been sleeping in it, there were no evidences of the extraordinary invasion mentioned by the drugged man. It was a small room--the chambers were of that kind which are let furnished--and very neat. A safe with a combination lock stood in a corner. The window was open about a foot at the top. Smith tried the safe and found it fast. He stood for a moment clicking his teeth together, by which I knew him to be perplexed. He walked over to the window and threw it up. We both looked out. "You see," came Weymouth's voice, "it is altogether too far from the court below for our cunning Chinese friends to have fixed a ladder with one of their bamboo rod arrangements. And, even if they could get up there, it's too far down from the roof--two more stories--for them to have fixed it from there." Smith nodded thoughtfully, at the same time trying the strength of an iron bar which ran from side to side of the window-sill. Suddenly he stooped, with a sharp exclamation. Bending over his shoulder I saw what it was that had attracted his attention. Clearly imprinted upon the dust-coated gray stone of the sill was a confused series of marks--tracks call them what you will. Smith straightened himself and turned a wondering look upon me. "What is it, Petrie?" he said amazedly. "Some kind of bird has been here, and recently." Inspector Weymouth in turn examined the marks. "I never saw bird tracks like these, Mr. Smith," he muttered. Smith was tugging at the lobe of his ear. "No," he returned reflectively; "come to think of it, neither did I." He twisted around, looking at the man on the bed. "Do you think it was all an illusion?" asked the detective. "What about those marks on the window-sill?" jerked Smith. He began restlessly pacing about the room, sometimes stopping before the locked safe and frequently glancing at Norris West. Suddenly he walked out and briefly examined the other apartments, only to return again to the bedroom. "Petrie," he said, "we are losing valuable time. West must be aroused." Inspector Weymouth stared. Smith turned to me impatiently. The doctor summoned by the police had gone. "Is there no means of arousing him, Petrie?" he said. "Doubtless," I replied, "he could be revived if one but knew what drug he had taken." My friend began his restless pacing again, and suddenly pounced upon a little phial of tabloids which had been hidden behind some books on a shelf near the bed. He uttered a triumphant exclamation. "See what we have here, Petrie!" he directed, handing the phial to me. "It bears no label." I crushed one of the tabloids in my palm and applied my tongue to the powder. "Some preparation of chloral hydrate," I pronounced. "A sleeping draught?" suggested Smith eagerly.