"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." "Decidedly awkward for Sir David," said Gimblet meditatively, "but after all, some one else might have fired off the rifle after he had cleaned it." Mark shook his head gloomily. "There are difficulties about that," he said. "It happens that David is very fussy about his guns, always cleans them himself, you know, and won't let another soul touch 'em. And though he keeps them in the gunroom like the rest of us, he's got his own particular glass-fronted cupboard which he keeps the key of himself. My uncle and I share one between us, and generally leave the key in the lock, so that the keeper can get at the guns, which we never bother to clean ourselves. Not so David. Ever since we were boys he's had his own private cupboard, and no one but himself has ever been allowed to open it. We always spent our holidays here, and my uncle let us behave as if we were at our own house. David took out the key for the sergeant to use, and when he was asked if anyone else could have got at the rifle, he replied that it was impossible, as the key had been in his pocket the whole time, except for an hour or two while he was asleep, when it had lain on the table by his bedside." "Did he deny having told Miss Byrne he had cleaned the rifle?" asked Gimblet.