A colorless color, like the dead gray of ashes; a skin like that of an African savage from which all but the last vestige of color had been drained. It was transparent, parchment-like, and even in the light of the room that glowed from some hidden source, he could see the throbbing lines of blood-vessels that showed livid through the translucent skin. And he remembered, now, the fingers, half-seen in his moments of awakening--they were like clinging tendrils, colorless, too, in that ashy gray, and showed the network of veins as if each hand had been flayed alive. * * * * * The observer found himself analyzing, comparing, trying to find some earthly analogy for these unearthly creatures. Why did he think of potatoes sprouting in a cellar? What possible connection had these half-human things with that boyhood recollection? And he had seen some laboratory experiments with plants and animals that had been cut off from the sunlight--and now the connection was clear; he knew what this idea was that was trying to form. These were creatures of the dark. These bleached, drained faces showed skin that had never known the actinic rays of the sun; their whole framework proclaimed the process that had been going on through countless generations. Here was a race that had lived, if not in absolute darkness, then in some place where sunlight never shone--a place of half-light--or of clouds. "Clouds!" The exclamation was startled from him. And: "Clouds!" he repeated meditatively; he was seeing again a cloud-wrapped world in the eye-piece of a big refracting telescope. "Blanketed in clouds," Professor Sykes had said. The scientist himself was speaking to him now in bewildered tones. "Clouds?" he inquired. "That's a strange remark to make. Where are we, Lieutenant McGuire? I remember nothing after you fired. Are we flying--in the clouds?" "A long, long way beyond them, is my guess," said McGuire grimly. It was staggering what all this might mean; there was time needed for fuller comprehension. But the lean bronzed face of the flyer flushed with animation, and in spite of the terrors that must surely lie ahead he felt strangely elated at the actuality of an incredible adventure. * * * * * Slowly he got to his feet to find that his muscles still were reluctant to respond to orders; he helped the professor to arise. And from the group that drew back further into the far end of the room came a subdued and rasping tumult of discordant sound. One, seemingly in charge, held a weapon in his hand, a slender tube no thicker than a common wire; and ending in a cylinder within the creature's hand. He pointed it in threatening fashion while his voice rose in a shrill call. McGuire and Professor Sykes stood quiet and waited for what the next moment might have in store, but McGuire waved the weapon aside in a gesture that none could fail to read.