He stared up at the sky, and realized that this too didn't look "normal." It wasn't, it couldn't be, the sky under which he had lived for most of his life. And the idea of living under a different sky didn't surprise him. It was an idea to which he must long have been accustomed. Two days later they reached the edge of the swamp. "I found you near here," said the Professor. He waved his arm vaguely. "You were wandering around, covered with mud." It didn't look familiar. Nor did it look as dangerous as he had expected it to look. He asked, "Why did we leave this neighborhood? Why didn't we stay and look for the plane that had crashed?" "For one reason," said the Professor gently. "Because at the time I didn't realize that there had been a plane. For another, because we were--shall I say, not popular?" "Why? Why weren't we?" A chuckle from Angel interrupted him. "People don't like to lose chickens." "I see." "Nor clothes," added the Professor. "Remember that I supplied you with garments that were hanging on a clothesline. Perhaps I should have mentioned that the farmer's wife who discovered her loss tried to extract payment from me by means of a shotgun." Crusoe nodded slowly. "By now, you assume, the memory of the loss will have grown faint?" "I hope so. We shall, of course, do our best not to attract attention." They moved into the swamp. It was gloomy, but not, thought Crusoe, frightening. There must have been no more than light rains during the past weeks, for at first they found it possible to walk along dry paths, and here and there were pools of mud where ordinarily there must have been water. But as they penetrated further in, the mud became more liquid. The leaves of the trees overhead shut out most of the light, and they walked over soft carpets of moss and decaying leaves. The odor too became unpleasant, the odor of mud flats and stagnant water, of small dead animals and impure, stinking marsh gas. "Where are we headed for?" said Angel uneasily. "This is kind of dark--" "Not too dark to see," said Crusoe. "But I perceive no signs of there having been a crash." "Nor do I," agreed the Professor. "However, the swamp covers an area of roughly twenty square miles. It will take us a considerable time to explore it all." And in those twenty square miles was the danger which he had felt hanging over him. He suddenly began to wonder what he would find. A crashed plane? No, it would be more than that. A crashed plane wouldn't explain why the people acted and talked so queerly, why the food didn't taste right, nor the sky look right. * * * * * The following day Angel stumbled over a half-hidden log and almost stepped into a trap. As the steel jaws snapped on the log instead of on his foot, Crusoe thought of another trap, a trap not of steel, but more relentless, one that gripped more firmly than this ever would. Had it shut recently, or was it going to shut?