"Take him off! Take him off!" It was an eery, strangled shriek from one of the male prisoners in the throes of a nightmare. With a startled curse the guard thudded to his feet, peered tensely into the darkness, his weapon sending twin milky beams of the powerful ionizing ray toward the source of the sound. * * * * * The dreamer had awakened, still gasping in the grip of fear, and other disturbed sleepers were grumbling. "Better go easy, you fools," the pirate warned them. "Yer just in luck that I didn't let loose a couple bolts on ye. Got a good notion to do it, anyway." He played the dangerous little spots of light around, amused as the prisoners scrambled for safety, but with no real intention of releasing the deadly electric charge along the paths provided for it. This cruel pleasure cost him his life. As he turned his back Quirl leaped. His iron-hard forearm rose and fell, and the edge of his hand came down on the back of the pirate's thick neck. There was a muffled crack and he slumped to the platform grating. Quickly the officer stripped off the man's harness and buckled it around his own naked chest. The electrogun had been uninjured, and hooked to the belt was also the riot club, a truly appalling thing at close quarters. Quirl carried the body down, laid it prone in the corner he had occupied, snapped on the waistlock, and threw a ragged old blanket over the hairy legs. In the forthcoming disturbance, if anyone looked in, he would think the inert form a sleeping prisoner, and that the guard had deserted post. Quirl had feared an outbreak among the prisoners, but they were so apathetic that they paid little attention. Perhaps they thought it was Quirl who had been killed, and he did not dare even a whispered farewell to the girl he knew was watching somewhere in the darkness. Much to Quirl's delight, the long, tubular passage was deserted. Here the centrifugal gravity was less than it had been in the hold. A weird place, this central tube, where every direction was down, and a man could walk on his ceiling, his floor, his walls with equal facility. No top nor bottom--just a long, smooth tube with numerous enigmatic doors leading to--where? At least it was easy to tell where the bow of the ship was. A light shone through a transom over the door to the navigating room. Should he try to hold up the navigating officer? He decided against that. There would be at least three men in there, and it was the custom to keep those quarters locked. "If only I knew where they generate the invisibility field!" he muttered, as he stood irresolute. * * * * *