They examined the parchment plans. They tore through Martian crates and boxes searching for the proper parts. They used tools made for tentacles instead of hands. They toiled like demons. A dream not begun in human minds gripped them. It was only a hope, now, for they were sure that they did not have enough time. Give back a world. Give Mercury a day and night. Spread out the terrible sunlight and darkness. Balance the two to temper each other. Let the frozen air turn to warm wind, and the snow and frost melt. Let the fierce sunlight be filtered by clouds and atmosphere. Let vegetation grow again in tropic lushness. Let the mines be reopened. And if it was possible, too, let the attack on the camp be lifted, and those still alive there, survive. There was even a wish among these three men that they themselves might not be destroyed. * * * * * Again Rick Mills had to shove the thought of Anne Munson almost angrily from his mind. It was a mere frivolity, useless and aching in these grim circumstances. A futile wistfulness, worse than the rest. Time passed. One by one the tasks were finished. Now the men had a Martian generator going, a queer, flat device to produce electric power and to free neutrons from beryllium. Exciter neutrons for those great jet tubes. Could it be believed that at last they had won nineteen hours of toil in their race to finish the job here, before Fane managed to kill them? They had fed huge quantities of familiar powder of uranium into the fuel blowers. They had set cables and grids into place. And still they continued to line things up, getting ready. During all this time there was only ominous, intermittent thudding, as from far away. "Fane's gathering his robot forces," Finden said anxiously. "And now he can at least tear at the vents of the tubes, up above." "I hope it won't matter," Rick answered. They couldn't search out and understand everything that was here. The instruments that might have warned, or the weapons that might have defended them. But optimism came at last. Though it wavered some when they heard a faint grinding sound which seemed deep beyond the walls, but came closer. They hurried to hook up the last cable. The thing that exploded must have been a mole-torpedo that drilled through rock and steel as fast as a man can walk. The walls of this vault did not break fully even under the Titanic force that hit them from outside. They bulged inward. A great section of the roof came down. Two of those huge jets were smashed. The whole chamber seemed to swing like a pendulum. A cable snapped in a flash of electric fire that consumed it. Rick Mills hardly knew where he was now. He was too stunned. Lattimer was moveless beside him on the floor. Finden crawled on his elbows. Blood dribbled from his mouth. Rick had closed the main switch but the great apparatus here was not functioning. Maybe he dreamed it, but Rick was sure he heard Fane's bitter laugh.