"That's what she said."
"Who?" asked Grant, surprised.
"Miss Dinmont. When I told her I hadn't done it."
"Oh? Well, it's a simple process of elimination, you see. And everything fits in too well for the possibility of a mistake. Even down to this." And picking up Lamont's hand from where it lay on the counterpane, he indicated the scar on the inside of his thumb. "Where did you get that?"
"I got it carrying my trunk up the stairs to my new rooms in Brixton — that morning."
"Well, well," said Grant indulgently, "we won't argue the affair now, and you're not well enough to make a statement. If I took one now, they'd hold it up to me that I had got it from you when you weren't compos mentis."
"My statement'll be the same whenever you take it," the man said; "only, no one will believe it. If they would have believed it, I wouldn't have run."
Grant had heard that tale before. It was a favourite gambit with criminals who had no case. When a man plays injured innocence, the layman immediately considers the possibility of a mistake; but the police officer, who has a long acquaintance with the doubtedly guilty, is less impressionable — in fact, is not impressed at all. A police officer who was impressed with a hard-luck story, however well told, would be little use in a force designed for the suppression of that most plausible of creatures, the criminal. So Grant merely smiled and went back to the window. The loch was like glass this evening, the hills on either side reflected to their last detail in the still water. Master Robert rode below the boathouse — "a painted ship" — only that no paint could reproduce the translucence of the sea as it was now.
Presently Lamont said, "How did you find where I had come to?"
"Fingerprints," said Grant succinctly.