"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?"
"You see," said Mark, "when the Crianan man had got hold of the boots that matched the footprints, he was no end excited by his success. Pleased to death with himself, he was. And he was as keen as mustard on following up his rotten clue. The next thing he did was to want a look at David's guns. Of course we didn't make any objection to that, though if I'd known--well, it's no earthly thinking of that now. So off we all marched in procession to the gun-room, and it didn't take long to see that the only one of the whole lot there that hadn't been cleaned since it was last fired was the Mannlicher David had shot his stag with the day before. The silly ass of a constable took it up and squinted through it as solemn as a judge, and then he just handed it to my cousin, and 'What have you to say to this, Sir David?' says he. Infernal cheek! 'I shot it off yesterday, and haven't had time to clean it since,' said David, and I, for one, could have sworn he was speaking the truth. Why not, indeed? There was nothing improbable about it. But the dickens of the thing was that while we were all out of the house, and he had the place to himself, the policeman had routed out poor Miss Byrne and badgered her for an account of all that had happened the evening before; and she, without a thought of doing harm to any of us--I'm convinced she's as sorry for it now as I am myself--had mentioned incidentally that David had told her, when she saw him half an hour before the murder, that he'd just been cleaning his rifle. She'd told me so, too, as far as that goes, when she passed through the billiard-room on her way to the library. I happened to ask her if she knew what he was up to."