“It’s the bottom staircase, of course,” the inspector said; and we tramped down into the basement. A little way from the stairfoot Hewitt opened a cupboard door, which enclosed a receptacle for coals. “They still keep the coals here, you see,” he said, striking a match and passing it to and fro near the sloping roof of the cupboard. It was of plaster, and covered the under-side of the stairs. “And now for the fifth dancer,” he said, throwing the match away and making for the staircase again. “One, two, three, four, five,” and he tapped the fifth stair from the bottom. “Here it is.” The stairs were uncarpeted, and Hewitt and the inspector began a careful examination of the one he had indicated. They tapped it in different places, and Hewitt passed his hand over the surfaces of both tread and riser. Presently, with his hand at the outer edge of the riser, Hewitt spoke. “Here it is, I think,” he said; “it is the riser that slides.” He took out his pocket-knife and scraped away the grease and paint from the edge of the old stair. Then a joint was plainly visible. For a long time the plank, grimed and set with age, refused to shift; but at last, by dint of patience and firm fingers, it moved, and in a few seconds was drawn clean out from the end, like the lid of a domino-box lying on its side. Within, nothing was visible but grime, fluff, and small rubbish. The inspector passed his hand along the bottom angle. “Here’s a hook or something, at any rate,” he said. It was the gold hook of an old-fashioned earring, broken off short. Hewitt slapped his thigh. “Somebody’s been here before us,” he said “and a good time back too, judging from the dust. That hook’s a plain indication that jewellery was here once, and probably broken up for convenience of carriage and stowage. There’s plainly nothing more, except--except this piece of paper.” Hewitt’s eyes had detected--black with loose grime as it was--a small piece of paper lying at the bottom of the recess. He drew it out and shook off the dust. “Why, what’s this?” he exclaimed. “More music! Why, look here!” We went to the window, and there saw in Hewitt’s hand a piece of written musical notation, thus:-- Hewitt pulled out from his pocket a few pieces of paper. “Here is a copy I made this morning of the ‘Flitterbat Lancers,’ and a note or two of my own as well,” he said. He took a pencil, and, constantly referring to his own papers, marked a letter under each note on the last-found slip of music. When he had done this, the letters read:-- _“You are a clever cove whoever you are but there was a cleverer says Jim Snape the horney’s mate.”_