He crept slowly down the shadowy yard, past the deserted hulls of spaceships. He came to a wire fence and sensed the high-voltage electricity running through it. Gauging his distance carefully, the Quedak jumped safely through one of the openings in the mesh. This was a very different section. From here the Quedak could smell water and food. He moved hastily forward, then stopped. He sensed the presence of a man. And something else. Something much more menacing. * * * * * "Who's there?" the watchman called out. He waited, his revolver in one hand, his flashlight in the other. Thieves had broken into the yards last week; they had stolen three cases of computer parts bound for Rio. Tonight he was ready for them. He walked forward, an old, keen-eyed man holding his revolver in a rock-steady fist. The beam of his flashlight probed among the cargoes. The yellow light flickered along a great pile of precision machine tools for South Africa, past a water-extraction plant for Jordan and a pile of mixed goods for Rabaul. "You better come out," the watchman shouted. His flashlight probed at sacks of rice for Shanghai and power saws for Burma. Then the beam of light stopped abruptly. "I'll be damned," the watchman said. Then he laughed. A huge and red-eyed rat was glaring into the beam of his flashlight. It had something in its jaws, something that looked like an unusually large cockroach. "Good eating," the watchman said. He holstered his revolver and continued his patrol. * * * * * A large black animal had seized the Quedak, and he felt heavy jaws close over his back. He tried to fight; but, blinded by a sudden beam of yellow light, he was betrayed by total and enervating confusion. The yellow light went off. The black beast bit down hard on the Quedak's armored back. The Quedak mustered his remaining strength, and, uncoiling his long, scorpion-jointed tail, lashed out. He missed, but the black beast released him hastily. They circled each other, the Quedak hoisting his tail for a second blow, the beast unwilling to turn loose this prey. The Quedak waited for his chance. Elation filled him. This pugnacious animal could be the first, the first on this planet to experience the Quedak mission. From this humble creature a start could be made.... The beast sprang and its white teeth clicked together viciously. The Quedak moved out of the way and its barb-headed tail flashed out, fastening itself in the beast's back. The Quedak held on grimly while the beast leaped and squirmed. Setting his feet, the Quedak concentrated on the all-important task of pumping a tiny white crystal down the length of his tail and under the beast's skin.