Within seconds they were speeding to the outer lock and Bejamel's ship. It was there that the robot-proctor left them, and hurried to the lower chamber where the pulsing generators sang their eternal threnody of unlimited power. Unnoticed he gained the great metalo-plastic doors that divided the vast chambers from the anti-gravity repulsor machinery. Unhesitatingly, it directed a thin pencil of force at an orifice slightly above the center of the great doors, just as Perlac had explained over and over, and the massive portals parted slowly, remaining open. Robots of the lower grades worked among the maze of towering machinery, oiling, testing, doing a multitude of tasks. But the robot-proctor, without paying them any attention, seemed to suddenly open at the side and an electro-flash gun, of large size, magnified by the Venusian scientists and raised to many times its normal power, came into view from the aperture. Without making a sound, without even a beam of light, the fatal weapon was aimed at the very heart of the colossal motors and generators, wheel and pistons seemed to warp, shrink and disappear uncannily; the steady throbbing hum of the degravitator, lost its smooth rhythm and thereafter large sections of machinery disappeared under the relentless action of the supernal fire being directed at them. Instantly the robots came to life, for a moment they milled wildly, as if this supreme emergency were something they were not able to cope with, and then they saw the new robot in their midst. Their synthetic brains activated only to the repair and maintenance of the machines, and to their safeguard, focused on the attacker, and its removal was instantly their immediate task. They attacked _en masse_, but the robot-proctor eluded them among the mazes of metalo-plastic, of bery-plastic rods and generators, and the tremendous motors which were being eaten by an invisible leprosy. With a swift slash of the electro-flash gun, the robot-proctor caused havoc among the robots that pursued him, legs, arms, even heads wavered and disappeared as the electronic balance was completely disrupted by the flash. A tremor seemed to shake the gigantic Sphere. By now, the great degravitator chamber was in shambles, and the remaining motors were unable to cope with the awful pressure of the gravity of the giant planet. With one final murderous sweep of the electro-flash, that seemed to shear like an invisible scimitar through machinery, robots and everything in its path, retreated as it had come, racing upwards towards the Sphere's emergency locks. There was no apparent pursuit. Only the vivid scarlet lights of imperative emergency, flooding what had been the degravitator chamber were witnesses to the destruction.