He pointed his tube at Dex Harlow, lying unconscious on the floor. There he hesitated an instant, his soft little mouth slobbering in his rage and pain. Then he let the tube sink slowly off its line. He gave another command. The four guards picked the Earthman up and carried him to the metal torture-plate on which the slave had met his death. The tall leader's eyes gleamed with vicious hatred as the limp body was fastened to the metal. Mouthing and squealing with the pain of his seared arm-stump, he wobbled toward the lever, a mere turn of which would readily convert the plate into a bed of agony. CHAPTER VII _In the Power-House_ Alone in the prison room, after Dex had been dragged away to be subjected to the Rogan inquisition, Brand gnawed at his fingers and paced distractedly up and down the stone flooring. For a while he had no coherent thought at all; only the realization that his turn came next, and that the Rogans would leave no refinement of torment untried in their effort to wring from him the secret of the atomic engine. He went to the window, and absent-mindedly stared out. The whining hum from the great domed building off to the right, like the high-pitched droning of a swarm of gargantuan bees, came to his ears. He listened more intently, and leaned out of the window to look at the building. Under that dome, it came to him again, was, in all probability, the mainspring of the Rogan mechanical power. If only he could get in there and look around! He might do some important damage; he might be able to harass the enemy materially before the time came for him to die. He leaned farther out of the window, and examined the hundred feet or so of sheer wall beneath him. He saw, scrutinizing it intently, that the stone blocks that composed it were not smooth cut, but rough hewn, with the marks of the cutters' chisels plainly in evidence. Also there was a considerable ridge between each layer of blocks where the Rogans' mortar had squeezed out in the process of laying the wall. Never in sanity would a man have thought of the thing Brand considered then. To attempt to clamber down that blank wall, with only the slight roughness of the protruding layers of mortar to hang on to, was palpable suicide! * * * * * Brand shrugged. He observed that to a man already condemned to death, the facing of probable suicide shouldn't mean much. With scarcely an increase in the beating of his heart, he swung one leg out over the broad sill. If he fell, he escaped an infinitely worse death; if he didn't fall, he might somehow win his way into that domed building whence the hum came. Cautiously, clutching at the rough stone with finger tips that in a moment or two became raw and bleeding masses, he began his slow descent. As he worked his way down, he slanted to the right, toward the near wall of the retaining yard whose end was formed by the round structure that was his goal.