Then Kirk led the way up the broad, thickly-carpeted staircase to the floor above. Entering an open door leading from the square landing, he touched an electric switch, revealing a small elegantly-furnished room, a boudoir, upholstered in dark red silk. The walls were enamelled dead white, relieved by a beading of gold, and set in the panels were two fine paintings of the modern Italian school. The red room was a veritable nest of luxury, with low easy chairs, a cosy corner near the fire, and a small reading table, whereon stood a selection of the latest novels from the library. In the cosy corner I noticed that the cushions were crushed, just as they had been left by the unfortunate girl as she had been aroused from her sleep by the entrance of the maid at early morning. One side of the room was occupied by a big bay window of stained glass, that probably faced a blank wall, while about four feet to the right of the cosy corner was a closed white-enamelled door--the door which gave entrance to the passage leading to the laboratory. The carpet was a pale grey, with a wreath of small roses running round the border, and before the door lay the white goatskin mat. My companion pointed to it, and I saw there the tell-tale stain of blood. The fire had been left just as it had died out on the morning of the tragedy. "You see," Kirk said, advancing to the closed door which led to the laboratory, "there is here a patent lock--an expensive make, which has but one key. This door I found still locked!" Opening it, we passed into a short passage about twelve feet long, closed by a similar door. This also he reopened, and I found myself in a large long apartment, very lofty, and well lit by a long high window along the side towards the street and at the end, while a skylight occupied part of the roof. Upon rows of shelves were many bottles of chemicals, retorts, and delicate experimental apparatus, while on the right was a small furnace. There were also three zinc-covered tables with the miscellaneous accumulation of objects which the owner of the place had been using. I saw a blocked-up door on the right, which my companion explained let into the conservatory over the portico. "Look!" whispered my friend in a low voice. "This way." And he switched on the lights at the further end of the great high apartment. I stepped forward at his side, until I distinguished, huddled up in the further corner, a human figure in dark grey trousers and black frock-coat. It seemed as though he had been propped in the corner, and his grey head had fallen sideways before death. I went further forward, holding my breath.