"The flower-bed outside the library window showed them plainly; the ground beyond that was mossy, and there were no other marks. We divided into two parties, one going west down the side of the loch, and the other north and east over the hills. Till ten o'clock or later we beat the country, searching behind every rock, and going through the woods and bracken in a close line. But we saw no sign of a stranger, and came back at last, dead beat, for food and a rest. When we got back we found that the policeman left in charge had been nosing about, and whiling away his time by collecting the boots of every one in the house and fitting them to the footprints on the flower-bed. As bad luck would have it, David's shooting-boots exactly fitted the marks." "His shooting-boots?" said Gimblet. "He wouldn't be wearing shooting-boots after dinner." "That's what he said himself, and there seems no imaginable reason why he should have worn them, unless--" Mark hesitated for a moment, and then went on in a tone perhaps rather too positive to carry complete conviction to a critical ear. "Of course not. He can't have put them on after dinner. The idea is ludicrous. He must have made those footmarks earlier in the day." "Is that what he himself says?" asked the detective. He had finished eating, and was leaning back in his chair with that air of far-off contemplation which those best acquainted with him knew was habitually his expression when his attention and interest were more than usually roused. "No," admitted Mark regretfully. "He doesn't. He sticks to it that he'd never been near the flower-bed, with boots, or without them; it's my belief his memory has been affected by the shock of all this. And he would insist on talking to the police, though they warned him that what he said might be used against him. I did all I could to stop him, but it was no good. It really looked as if he was doing his best to incriminate himself." "How was that? What else did he say?"