A light began to appear ahead. I could see more of that cavern--even the rock-ribbed ceiling high overhead. I can't express just what I was thinking at that moment, but I saw Doc Champ kick at a mound of something underfoot. The mound crumbled; Doc stooped and picked up a round object, like a disk of rusted metal, and looked at it with a kind of stark wonder. Then he threw it away and we followed Rog Tanlu. The light grew brighter, became a huge square of blustery, blue-white chaos. We were standing as if just within the maws of a Gargantuan doorway--an open doorway through which we could look out over a scene of inexpressible dreariness. You've seen pictures of the Antarctic? Titanic masses and pinnacles of ice, frozen white barrens, a land without feeling or soul? It was like that. "We are looking through the Ice Stone." Rog Tanlu's voice was all but snatched away by that glacial blast swishing in our faces. "I set it up like a door--a door leading from my laboratory to the outside. The light you see, and the wind, has taken half a million years to get through." Doc Champ was tugging at the collar of his coat, and my own teeth were chattering. Rog Tanlu motioned us to one side, out of that freezing blast. "You see what we were up against?" he smiled. "Our space explorations had killed the hope that some other planet in the system might offer a suitable refuge where humans could live under anything like natural conditions. "Moreover, there were social troubles. Politicians, philosophers and sociologists all combined to control science. A scientist had to get a special permit before he could conduct any new line of inquiry. "So I built this laboratory--ten miles from the vitro-domed city of Iralnard--partly to escape governmental interference and partly to keep from being spied upon by Darlu Marc, another experimentalist and personal enemy of mine. I worked here alone, except for one laboratory assistant--Eyoaoc Eiioiei, as I called him. And here we created the Ice Stone. "As I have already explained, it is no material thing--merely a cube of specialized space, foreshortened, warped and curved to attain a specific result. Its action is very simple. It slows up a beam of light exactly as does a lens, but to an incomparably greater degree. And being composed of nothing tangible, it acts on any moving thing--particle, atom or electron--exactly as it does on light photons. "Thus a man can walk through the Ice Stone without sensing any change. Yet every function of his being is retarded, including mental processes. And when he emerges from the other side, approximately half a million years have elapsed. But once having touched it, say with his hand, he must not try to withdraw, for his hand will then be within a separate and distinct macrocosm, uninfluenced by anything outside, and he must follow on through.