Dex moistened his lips. An electric shock? No, it was something more terrible than that. Some other manifestation of the magnetic power the Rogans had harnessed--a current, perhaps, that depolarized partly the atoms of the body structure? He could only guess. But the convulsed face of the unfortunate victim showed that the torment, whatever it was, was devilish to the last degree! "That will be the next to the last fate reserved for you," the Rogan informed Dex, through Greca. "Death follows soon after that--but not too soon for you to see and feel what waits for you behind the barred door!" And he nodded toward the cage-entrance affair, from which came the musky, reptilian stench. "Now that you have seen something of what will happen to you if you refuse to tell us what we want to know, we shall proceed," said the leader. * * * * * He pointed toward one of the gargantuan work benches, and two of the Rogans slid down from it a contrivance that looked familiar to Dex. An instant's scrutiny showed him why it was familiar: it was a partly dismantled atomic motor. In spite of the ordeal that faced him, Dex felt a thrill of elation as he looked at the motor. In its scattered state, it told a mute story: a story of long and intensive study by the Rogans, which had yielded them no results! Only too obviously, the intricate secret of atomic power had not let itself be solved. On the heels of the elation that filled his heart, came a sickening realization of his dilemma. He could not have told the Rogans what they wanted to know even if he had wished to! He himself didn't know the principles of the atomic engine. As Brand had remarked, he was no space navigator; he was simply a prosaic lieutenant, competent only at fighting, not at all versed in science. He knew, though, that it would do no good to assert his ignorance to the Rogans. They simply wouldn't believe him. "You will rebuild this engine for us," ordered the tall leader, "showing us the purpose of each part, and how the power is extracted from the fuel. After that you will set it running for us, and instruct us in its control." Dex braced himself. His final moment had come. By way of indicating his refusal he looked away from the dismantled motor and said nothing. The Rogan repeated his command. Dex made no move. Then the leader acted. He said something to the Rogan guards who had been standing by all this while, alert against an outbreak from their prisoner. Dex was caught up, carried to one of the metal racks, and thrown down on its calibrated bed. Loops of metal, like handcuffs, were snapped around his wrists and ankles; and a metal hoop was clamped over his throat, pinning him to the torture rack. Resistance would have been useless, and Dex submitted quietly. * * * * *