The words came back to me now. If it needed twenty drops to kill a strong man, surely a small dose could with safety be administered to a wiry little old man who, though decrepit, seemed still to possess considerable vitality. But would it be quite safe? Did I dare risk it? "A cup of tea will do just as well," I said carelessly, tossing aside my cigarette. "No, don't you move. I see you have everything ready, and there are cups up on the shelf. Let me make the tea. I like tea made in one way only." I felt quite guilty when he answered-- "You are very kind, sir; you are very kind; you are a gen'leman." It was easily and quickly done. I had my back to him. I poured the tea into the cups. Then I let about five drops of the fluid in the flask fall into a spoon. I put the spoon into his cup, and stirred his tea with it. In a few moments I saw he was growing drowsy. His bony chin dropped several times on to his chest, though he tried to keep awake. He muttered some unintelligible words. In a few minutes he was asleep. I took his pulse. Yes, it was still quite strong. I waited a moment or two. Then, slipping my hand into his jacket-pocket, I took out the bunch of keys noiselessly, turned out the gas-stove, and stepped quietly out of the room, closing the door behind me. CHAPTER SEVEN. TREADING AMONG SHADOWS. The house was found very dirty and neglected. It contained but little furniture. Dust lay thickly upon everything. The windows, I was almost tempted to think, had not been opened since Sir Charles had last lived there three years ago. There was also a damp, earthy smell in the hall. As I went slowly up the stairs, bare of carpet or any other covering, they creaked and groaned in a way that was astonishing, for the houses in Belgrave Street are not so very old. The noises the stairs made echoed higher up. I had decided to enter the rooms on the ground floor last of all. The first floor looked strangely unfamiliar. When last I had been here the house had been luxuriously furnished, and somehow the landing, in its naked state, seemed larger than when I remembered it. Ah! What fun we had had in that house long ago! My friends the Thorolds had entertained largely, and their acquaintances had all been bright, amusing people, so different, as I had sometimes told my friends, from the colourless, stupid folk whose company one so often has to endure when staying in the houses of acquaintances. I often think, when mixing with such people, of the story of the two women discussing a certain "impossible" young man, of a type one meets frequently. "How deadly dull Bertie Fairbairn is," one of them said. "He never talks at all." "Oh, he is better than his brother Reggie," the other answered. "Whenever you speak to Bertie he says, `Right O!'" The door of the apartment that had been the large drawing-room was locked. On the bunch of keys, I soon found the key that fitted, and I entered.