“Probably it isn’t. But it’s interesting. I suppose you must be right. I can’t see any other explanation, I’m bound to say. But it must have been a very curiously shaped object, to leave those marks. Or could it have been a number of things? And why should the dust have been scraped away like that? Something must have been drawn across the surface; something flat and smooth and fairly heavy.” He meditated for a moment. “It’s funny.” Alec stepped back from the fender. “Well, we don’t seem to be progressing much, do we?” he remarked. “Let’s try somewhere else, Sherlock.” He wandered aimlessly over towards the French windows and stood looking out into the garden. A sharp exclamation from Roger caused him to wheel round suddenly. The latter had descended from his chair, and was now standing on the hearth-rug and looking with interest at something he held in his hand. “Here!” he said, holding out his palm, in which a small blue object was lying. “Come and look at this. I stepped on it just now as I got down from the chair. It was on the rug. What do you think of it?” Alec took the object, which proved to be a small piece of broken blue china, and turned it over carefully. “Why, this is a bit of that other vase!” he said sagely. “Excellent, Alexander Watson. It is.” Alec scrutinised the fragment more closely. “It must have got broken,” he announced profoundly. “Brilliant! Your deductive powers are in wonderful form this morning, Alec,” Roger smiled. Then his face became more grave. “But seriously, this is really rather perplexing. You see what must have happened, of course. The vase got broken where it stood. In view of this bit, that’s the only possible explanation for those marks on the chimney-piece. They must have been caused by the broken pieces. And that broad patch was made by someone sweeping the pieces off the shelf—the same person, presumably, as picked up the larger bits round that ring.” He paused and looked at Alec inquiringly. “Well?” said that worthy. “Well, don’t you see the difficulty? Vases don’t suddenly break where they stand. They fall and smash on the ground or something like that. This one calmly fell to pieces in its place, as far as I can see. Dash it all, it isn’t natural!—And that’s about the third unnatural thing we’ve had already,” he added in tones of mingled triumph and resentment. Alec pressed the tobacco carefully down in his pipe and struck a match. “Aren’t you going the long way round again?” he asked slowly. “Surely there’s an obvious explanation. Someone knocked the vase over on its side and it broke on the shelf. I can’t see anything wrong with that.”