astronomer has or a physicist, who builds up the universe in just the same way.”
“But that’s a difficult thing to do,” I remarked, “to find a theory that fits all the facts.”
“Exceedingly difficult sometimes,” assented my companion, “because the facts often appear to be entirely contradictory. Really, facts are never contradictory—truth is always truth—the trouble is we can’t always tell what is fact and what is fiction. The hardest part of a detective’s work is to sift the wheat from the chaff—to get at the meaty, essential facts.
“Well, as you know, I started out with the theory of Tremaine’s guilt. More than that, I was morally certain that he was guilty, knowing what I knew of the man. And first of all, it was evident to me that no criminal as careful as he is would run the risk of going through that boathouse and committing a murder on the pier outside with young Graham sleeping on a cot a few feet away. I therefore deduced this bottle. Smell of it.”
He uncorked it and held it under my nose.
“Chloroform!” I said.
“Precisely,” and he corked it carefully and returned it to his pocket. “The boy’s story helped me to arrive at it. He had been awakened by that violent thunder-clap, but for the first moment he had found himself unable to move—dizzy, as he explained it.”
“But how did you know where to look for it?” I asked.
“Well, I knew that no experienced criminal would
