They landed with a thump which seemed to shake all life from two of them. Friday and Eliot Leithgow collapsed into inert heaps, asleep immediately. Carse extracted a ray-gun from the belt of Leithgow's suit and prepared to stand watch. But that was too much. He over-estimated his capacity. He had come through thirty hours of hellish sleep-denied delirium, and he could not stave sleep off any longer. He staggered and went down, and his eyelids were glued in sleep when his body hit the ground. But mechanically, with an instinct that sleep could not deny, his left hand kept clasped around the butt of the ray-gun.... * * * * * Satellite III's day has an average of seven hours' duration, her night of six. It was perhaps the last hour of daylight when the three metal and fabric-clad figures lying outsprawled on the little thumb-shaped piece of soil had landed. Now quickly the huge sweeping rim of Jupiter plunged down, and night fell over the land. Fierce darkness. Jungle and swamp awoke with their scale of savage life. Swift swooping shapes winged out from the trees, prey-hungry eyes gleaming green. And from the swamps came bellowings and stirrings from monster mud-encrusted bodies, awakening to their nocturnal quest for food. The night reechoed with the harsh cacophony of their cries. With lumbering caution, its smooth knob head waving on a long reptilian neck, its heavy armored tail dragging behind its body's folds of flesh, a giant night-thing came stumping out of a copse of jungle growth--a buru. Its eyes were watchful, but centered mainly on the pool of water to one side of the peninsula of firm soil. Its drinking water was there. With several pauses, it went right out on the spit, and a flat-bottomed foot twice the size of an elephant's missed one of the sleeping forms by inches. But the buru cared not for them. It was not a flesh-eater. Its undulating neck stretched far out; its head dipped; water was lapped up--until it caught sight of the uprooted giant stump lying pitched in the pool. The beast drank but little after that, and retreated as cautiously as it had come. Five or six of its fellows of the swamps followed at intervals to the water, grotesque hulking shapes, odorous and slimy with mud. All drank from the same spot; all ignored, save for a tentative rooting snuffle, the unconscious figures lying puny beneath them. But all noticed the twisted roots of the stump, sticking out in a score of directions, and avoided them. And then there came smaller, more cautious animals who did not drink from the favored spot, who surveyed it, sniffed, hesitated, and finally retreated. There was a good reason for this caution.