The green moon was still high in the sky as Ruth and Dixon emerged from the tunnel, but it was already beginning to drop gradually down toward the west. Dixon wheeled his disreputable flivver out of its nearby shed. With engine silent they started coasting down the rough winding road into the valley. For nearly two miles they wound down the long grade. Then, just as they reached the valley floor they saw, far up among the rocks to the left of the road, the thing they had been dreading--the bobbing opalescent globe that marked the presence of one of the Centaurians' hideous hybrids. The shimmering globe paused for a moment, then came racing down toward them. The need for secrecy was past. Dixon threw the car in gear and savagely pulled down the gas lever. With throttle wide open they hurtled around the perilous curves of the narrow road, but always in the rocks beside and above them they heard the scuttling progress of some huge, many-legged creature that constantly kept pace with them. They had occasional glimpses of the thing. Its pale jointed body was some twenty feet in length, and had apparently been developed from that of a centipede, with scores of racing legs that carried it with startling speed over the rocky terrain. The flivver raced madly on toward the blaze of kaleidoscopic colors that marked the Centaurians' camp. Crawford's home loomed up now barely a hundred yards ahead. As though sensing that its quarry was about to escape, the hybrid flashed a burst of speed that sent it on by the car for a full fifty yards, then down into the road directly in front, where it whirled to confront them. Dixon knew that he could never stop the car in the short gap separating them from that huge upreared figure, and to attempt swerving from the road upon either side was certain disaster. He took the only remaining chance. With throttle wide open he sent the little car hurtling straight for the giant centipede. He threw his body in front of Ruth, to shield her as much as possible, just as they smashed squarely into the hybrid. The impact was too much for even that monstrous figure. It was hurled bodily from the road to crash upon the jagged rocks at the bottom of a thirty-foot gully. There it sprawled in a broken mass, too hopelessly shattered to ever rise again. The flivver skidded momentarily, then crumpled to a full stop against the rocks at the side of the road. Dixon and Ruth scrambled from the wreckage and raced for Crawford's home, scarcely fifty yards ahead. * * * * * They entered the laboratory and Ruth went directly over to where the radio-projectile rested in a wall-rack. Dixon took the gleaming cylinder down to examine it. Tapering to a rounded point at the front end, it was nearly a yard long and about five inches in diameter.