“I’m a light sleeper,” Watson says, “but Holmes is a hardly a sleeper at all. So it happened often enough at 221B that I’d hear a sharp rap on my bedroom door. Three raps, usually. In the early days, I’d grope in the dark for a match and, like as not, knock the candlestick to the floor before I managed to light it. Candle wax on the carpet. Complaints from Mrs. Hudson. The day I noted the advertisement for Pyramid Night Light and Watch Holder I purchased one. If I’m going to rouse at some devil’s hour, I want to know which one.”