Suddenly, the moon tank shuddered beneath Alan's feet. They had come within range sooner than he had expected. He felt himself hurled away, and tumbled across the rocks as the tank burst briefly into flame, devouring in seconds the oxygen stored in the fuel tanks. With an eerie, noiseless blast, the tank exploded. Alan scrambled forward across the rocks. Somehow, he had managed to hold his atomic rifle. He wondered if the mechanism had been damaged by his fall. He didn't have time to think about it. The other tank, now less than fifty yards away, was coming toward him. He fired once, forced to reveal his position. A spacesuited figure fell from the tank, but another climbed up through the hatch to join the man still kneeling there. The tank was thirty yards away now, still coming. Concealed partially behind an out-cropping of rock, Alan fired again, saw a second figure tumble off the roof of the tank, rolling down a steep incline. The third man was returning his fire, but wildly. At the last moment he tried to scramble within the hatch, but his glassite helmet exploded as one of Alan's pellets caught it. The tank was upon him, its caterpillar treads rolling soundlessly across the rock. Flinging his rifle out of the way, Alan dove between the two great treads and clung there. He could feel the jagged rocks cutting into his spacesuit, scraping it, weakening the fabric. In seconds, the fabric would rupture. There was a hatch on the under-belly of the tank. Dragged along, Alan held on with one hand and pried at the hatch with the other. He was bruised and shaken by the rocks. The hatch swung clear. Alan chinned himself into the tank. A spacesuited figure sat over the controls. Another one was staring at Alan through the glassite helmet of a modern spacesuit. It was Laura. He didn't know if she would recognize him through the visor of his ancient suit. She screamed, "Alan! Look out!" Keifer was rising from the controls, plunging toward him. Alan met him half way over the open hatch, grappled with him there. In Keifer's hand was an atomic pistol. He couldn't bring it down to bear on Alan, but was beating him across the head with it, the sound of metal striking metal booming in Alan's ears. If his helmet had been glassite, he thought, Keifer could have killed him. He lost his footing and slipped, spread-eagling over the open hatch. Keifer fell on him, pushing, trying to force him through. "You can't stop the bomb," he said, his voice cold and metallic over the suit radio. "It's all automatic now." For answer, Alan swung his metal-shod fists at Keifer's glassite helmet. He felt himself slipping. In seconds, Keifer's weight would drive him through the hatch. He pounded the glassite helmet above him. Blindly, he kept on pounding it. His legs were slipping, dangling through the hatch over the jagged rocks. The slightest rip in the fabric of his suit would bring instant death.