She wanted desperately to run forward and learn what Phil intended to do, but she restrained herself and obeyed his order. She waited, and watched; and saw the young man stand up, look at the slowly advancing monster--and deliberately walk right into its path! Sue could not move from her fright. In a daze she saw Phil advance cautiously towards the amoeba and pause when within five feet of it. The thing stopped; remained absolutely motionless. She saw him take another short step forward. This time a pseudopod emerged, and reached slowly out for him. Phil avoided it easily, but by so narrow a margin that the girl's heart stopped beating. Then she saw him step back; and, snail-like, the creature followed, pausing twice, as if wary and suspicious. Slowly Phil Holmes drew it after him. To Sue, who did not know what was his plan, it seemed a deliberate invitation to death. She forgot about her father, lying inside the mangled borer, waiting. She did not see that Phil was leading the monster directly in front of it.... * * * * * It was a grotesque, silent pursuit. The creature appeared to be unalert; its movements were sloth-like; yet the girl knew that if Phil once ventured an inch too close, or slipped, or tried to dodge past it to the sphere, its torpidness would vanish and it would have him. His maneuvering had to be delicate, judged to a matter of inches. Tense with the suspense, the strain of the slow-paced seconds, she watched--and yet hardly dared to watch, fearful of the awful thing she might see. It was a fantastic game of tag her lover was playing, with death the penalty for tardiness. The slow, enticing movements were repeated again and again, Phil advancing very close, and stepping back in the nick of time. Always he barely avoided the clutching white arms that were extended, and little by little he decoyed the thing onward.... Then came the end. As Holmes was almost in front of the wrecked machine, Sue saw him glance quickly aside--and, as if waiting for that moment when he would be off guard, the monster whipped forward in a great, reaching surge. Sue's ragged nerves cracked: she shrieked. They had him! She started forward, then halted abruptly. With a tremendous leap, Phil Holmes had wrenched free and flung himself backwards. She heard his yell: "Now!" * * * * * There was a sputter from the bottom of the outstretched borer; then, like the crack of a whip, came a bellow of awful sound. A thick cloud of dust reared up, and the ear-numbing thunder rolled through the cavern in great pulsing echoes. And then Sue Guinness understood what the young man had been about. The disintegrators of James Quade's borer had sent a broad beam of annihilation into the monster. His own machine had destroyed his destroyer--and given his intended victims their only chance to escape from the dread fate he had schemed for them.