All sleepiness left him as he saw what it was he had picked up in his idle groping. It was clear as rock crystal, this queer, smooth cube. Quartz, unquestionably, but not in its usual hexagonal crystallized form. Somehow -- he could not guess the method -- it had been wrought into a perfect cube, about four inches in measurement over each worn face. For it was incredibly worn. The hard, hard crystal was rounded now until its corners were almost gone and the thing was beginning to assume the outlines of a sphere. Ages and ages of wearing, years almost beyond counting, must have passed over this strange clear thing.