Sue could see no trace of the creature in its pyre of slow-swirling dust. Caught squarely, its annihilation had been utter. And then, through the thunder that still echoed in her ear-drums, she heard a joyful voice. "We got 'em!" Through the dusty haze Phil appeared at her side. He flung his arms up exultantly, swept her off the ground, hugged her close. "We got 'em!" he cried again. "We're free--free to go up!" Professor David Guinness crawled from the borer. His face, for the first time since the descent, wore a broad smile. Phil ran over to him, slapped him on the back; and the older man said: "You did it beautifully, Phil." He turned to Sue. "He had to decoy them right in front of the disintegrators. It was--well, it was magnificent!" "All credit to Sue: she was my inspiration!" Phil said, laughing. "But now," he added, "let's see if we can fix those dead rocket-tubes. I have a patient up above--and, anyway, I'm not over-fond of this place!" * * * * * The three had won through. They had blasted four miles down from the surface of the earth. The brain of an elderly scientist, the quick-witted courage of a young engineer, had achieved the seemingly impossible--and against obstacles that could not have been predicted. Death had attended that achievement, as death often does accompany great forward steps; James Quade had gone to a death more hideous than that he devised for the others. But, in spite of the justice of it, a moment of silence fell on the three survivors as they came to the spot where his fate at last had caught up to him. But it was only a moment. It was relieved by Professor Guinness's picking up the chunk of radium ore his former partner had hewn from the cavern's wall. He held it up for all to see, and smiled. "Here it is," he said simply. Then he led the way into his earth-borer, and the little door closed quietly and firmly into place. For a few minutes slight tappings came from within, as if a wrench or a screwdriver were being used. Then the tappings stopped, and all was silence. A choke, a starting cough, came from beneath the sphere. A torrent of rushing sound burst out, and spears of orange flame spurted from the bottom and splashed up its sides, bathing it in fierce, brilliant light. It stirred. Then, slowly and smoothly, the great ball of metal raised up. It hit the edge of the hole in the ceiling, and hung there, hesitating. Side-rockets flared, and the sphere angled over. Then it slid, roaring, through the hole. Swiftly the spots of orange from its rocket-tube exhausts died to pin-points. There were now almost twenty of them. And soon these pin-points wavered, and vanished utterly.