Spectroscopic observations had revealed that the second planet possessed an atmosphere high in oxygen and showing traces of water vapor. It was a small world about the size of Mars and uncomfortably close to its flaming orange sun, but it had been his only bet. He glanced obliquely at the fuel gauge again. His lips thinned, and he dropped his eyes to the scanner. Immediately, the surface seemed to bounce up at him. Dense jungles. The sheen of an inland sea. The terrain flowed past like an immense relief map. Then he saw the city. * * * * * It rose at the edge of the sea, all turrets and spires and battlements like a walled medieval town. He caught a glimpse of quays with ships warped against them, of cultivated fields like a vast checkerboard. Then the Mizar had flashed past. The city seemed to dwindle and vanish, only the sparkle of orange sunlight on the spires lingering an instant longer. Jupiter Jones blew out his breath. His first reaction had been to swing the Mizar around, but caution prevailed. He was too old a hand at Galactic exploration to burst unannounced on an alien culture. The terrain below had been growing progressively rougher. Just ahead a range of mountains reared saw-edged peaks into the clouds. He nursed the Mizar along until the gorges fell away beneath him like blue-green troughs. There was no sign of habitation anywhere. He braked and banked, spiraling lower and lower, dropping into a deep valley with a river cutting through it like a silver thread. At the last moment, he frantically buckled himself down and cut in "George". Flame bellowed around the Mizar as the automatic landing jets burst into life. With a fierce crackling roar the star ship sliced through the tangled vegetation, came to rest a hundred meters from the river. Jupiter Jones threw off the safety straps, stood up, feeling a tingle of excitement take hold of him. He was down, the ship resting on the crust of a strange world. A world that might well be his home for the rest of his natural life. It was a dismaying thought. With gravity dragging at his feet once more, he moved to the transparent rind of the thermoplas blister and stared out. The landing jets had charred a huge swathe in the vegetation, charred it to the finest ash and baked the ground like brick, leaving a wall of jungle hemming the ship in. Nothing moved. He flicked on the outside amplifiers, but the silence was tomb-like. The thunder of his descent must have frightened off all the wild life. He was conscious of a cumulative weariness like an ache. Experience had taught him the necessity of being fresh before venturing into an alien environment. He entered his landing in the log, switched on the electronic alarm. "Let 'George' keep watch," he thought. "George's" senses were keener than any human's, and "George" could be depended on!