There was no doubt about it now. As his eyes accustomed themselves to the darkness, he saw that the strange crystal was glimmering with tiny fugitive lights deep within it like threads of sapphire lightnings. They were at its center and they seemed to him to come from the pale disk with its disturbing markings. And the disc itself was becoming larger ... the markings shifting shapes ... the cube was growing ... was it illusion brought about by the tiny lightnings....