Dr. Kemp's scientific pursuits have made him a very observant man, and as he recrossed the hall, he noticed a dark spot on the linoleum near the mat at the foot of the stairs. He went on upstairs, and then it suddenly occurred to him to ask himself what the spot on the linoleum might be. Apparently some subconscious element was at work. At any rate, he turned with his burden, went back to the hall, put down the syphon and whiskey, and bending down, touched the spot. Without any great surprise he found it had the stickiness and colour of drying blood.

He took up his burden again, and returned upstairs, looking about him and trying to account for the blood-spot. On the landing he saw something and stopped astonished. The door-handle of his own room was blood-stained.

He looked at his own hand. It was quite clean, and then he remembered that the door of his room had been open when he came down from his study, and that consequently he had not touched the handle at all. He went straight into his room, his face quite calm--perhaps a trifle more resolute than usual. His glance, wandering inquisitively, fell on the bed. On the counterpane was a mess of blood, and the sheet had been torn. He had not noticed this before because he had walked straight to the dressing-table. On the further side the bedclothes were depressed as if someone had been recently sitting there.