The pale, turquoise disk of Earth rode low in the heavens above the serrated Alps, towering above him, illuminating the rugged fastnesses in a sort of aqua glow. Earth, now at full, lighted Luna many times brighter than a full moon had ever lighted her. But the countless thousands of shadows cast by lava stalagmites, spires, boulders and mountain peaks were pits of nothingness. Crag walked into the Stygian blackness cast by a stalagmite and disappeared as completely as though swallowed up by a dark hole in the moon's surface. He passed on through the shadow and reappeared abruptly on the other side. He himself cast a long, black shadow, more weird because it appeared to be a black pit sliding over the floor of the crater. Instinctively Ron Crag crouched as the pencil of flame streaked past his head. He could not feel the heat through the insulated suit, but he knew it had missed him by scant inches. He wheeled and darted back into the shadow he had just quitted, his gun leaping into his hand. He saw a burly form dart into the shadow of a massive boulder across the basin from him. He started to snap a beam at it, but held his fire; the flare would only betray his own position. He could not see the slightest shape, the slightest trace of movement in the inky blackness of the other shadow. There was some compensation in knowing that the ambusher could not see him either. Without air to diffuse the earthlight, the shadows were sharp and distinct as though no light existed in all the universe outside their borders. He glanced in the direction from which his attacker had come. There in the north edge of the crater, in the mouth of the canyon, another catatread was parked. It was an old model, battered and eroded by time and hard usage. Ron Crag thought he recognized the steed; he had seen it once or twice down south, in the parking area back of the Tycho terradome. Realizing the identity of his assailant a sudden terror paralyzed him for a moment, but then it fled, leaving him trembling and angry. "Howdy, son," a sarcastic voice drawled into the earphones of his radarphone. "You shouldn't talk to yo'self about your rich lodes, else you should be sure your radarphone is cut off, so's pore luckless critters like me couldn't overhear ye." Crag bit his lip in anger and shame. The killer had heard his remark, got a directional fix on his position and-- "Joe Braun?" Crag grated into the transmitter in his helmet, forcing the quaver out of his voice. "Biggest, dirtiest claim jumper in all North Luna." "Nobody ever proved a thing on me," Joe Braun guffawed. "No! Or you'd be at the bottom of some crater," Crag retorted. "This time you've slipped." "Think so, feller? Think you'll be reportin' this?" Ron's flesh crept. There were few men on Luna who would match flame with this black-bearded killer. Those luckless ones who had challenged him were now piled at the bottom of various craters.