Roger frowned abstractedly. He was enjoying himself hugely. With his capacity for throwing himself heart and soul into whatever he happened to be doing at the moment, he was already beginning to assume the profound airs of a great detective. The pose was a perfectly unconscious one; but none the less typical. “Well, taking as our starting point the fact that the bullet was fired from a line which includes the chair in which Mr. Stanworth was sitting,” he began learnedly, “and assuming, as I think we have every right to do, that it was fired between, let us say, the hours of midnight and two o’clock this morning, the first thing that strikes us is the fact that in all probability it must have been fired by Mr. Stanworth himself.” “We then remember,” said Alec gravely, “that the inspector particularly mentioned that only one shot had been fired from Mr. Stanworth’s revolver, and realise at once what idiots we were to have been struck by anything of the kind. In other words, try again!” “Yes, that is rather a nuisance,” said Roger thoughtfully. “I was forgetting that.” “I thought you were,” remarked Alec unkindly. Roger pondered. “This is very dark and difficult,” he said at length, dropping the pontifical manner he had assumed. “As far as I can see it’s the only reasonable theory that the second shot was fired by old Stanworth. The only other alternative is that it was fired by somebody else, who happened to be standing in a direct line with Stanworth and the vase and who was using a revolver of the same, or nearly the same, calibre as Stanworth’s. That doesn’t seem very likely on the face of it, does it?” “But more so than that it was a shot from Stanworth’s revolver which was never fired at all,” Alec commented dryly. “Well, why did the inspector say that only one shot had been fired from that revolver?” Roger asked. “Because there was only one empty shell. But mark this. He mentioned at the same time that the revolver wasn’t fully loaded. Now, wouldn’t it have been possible for Stanworth to have fired that shot and then for some reason or other (Heaven knows what!) to have extracted the shell?” “It would, I suppose; yes. But in that case wouldn’t you expect to find the shell somewhere in the room?” “Well, it may be there. We haven’t looked for it yet. Anyhow, we can’t get away from the fact that in all probability Stanworth did fire that other shot. Now why did he fire it?” “Search me!” said Alec laconically. “I think we can rule out the idea that he was just taking a pot-shot at the vase out of sheer _joie de vivre_, or that he was trying to shoot himself and was such a bad shot that he hit something in the exact opposite direction.” “Yes, I think we might rule those out,” said Alec cautiously. “Well, then, Stanworth was firing with an object. What at? Obviously some other person. So Stanworth was not alone in the library last night, after all! We’re getting on, aren’t we?”