Hafnagel held him on his shoulders, and Bill leaned into the port and ran his educated fingers over the smooth surfaces therein. He found the lock, a raised set of thumb-sized nodes and two bars that would not move for him. Frantically he searched his mind for every trick he knew of locks and bolts and all such mechanisms. He began trying various manipulations, all his years of magic concentrating in the flying fingers. The metal plate slid without sound into the sidewall, leaving an opening through which a diffused green glow poured out into his face. Bill thought of the peculiar way he had moved the node and bar, and node and bar.... In all the world, it was not likely that any man except a trained magician would have touched them in the right sequence. He puckered his lips and whistled without noise. "What if I'd studied for the law, like Mother wanted me to?" he murmured. "Holy cats!" Taking the initiative, he hoisted himself from Hafnagel's shoulders and wormed into the hole. The passage was slick without being actually greased, and within seconds he rose to his feet in the first room of the great disk. Trace followed, then the others, Hafnagel coming last. They gathered in a taut, apprehensive group, staring about them. The room was empty of life. There was no sound in the saucer save for their own quick breathing. CHAPTER XI Without a glance at the curious furnishings of the craft, Trace Roscoe headed for the door on the right-hand side. It was a tall rectangle, like an earth-made door, but without knob; as Trace came within a foot of it, it slid into the wall so briskly that he would not have touched it had he been coming at a dead run. Electric eye, or the same principle, he thought, striding forward. Nor was there anyone in this room, which was plainly a sleeping chamber. Trace marched for the next barrier, but Slough darted over to investigate a narrower door, and thus discovered the first two Graken. The vanishing portal showed a lavatory, and the pair of greenies stared up, startled, from a massive washbowl, in which they had been bathing their faces and bare arms. Their helmets were slung on wall pegs. Both of them went for their pistols, but Trace, not so surprised as they, beat them to the draw. He fired over the tiny man's shoulder, and the Graken died, their flesh dissolving into steam and fragments. Barbara Skye said her first word in an hour. It was triumphant, but quite unprintable. Jane Kelly said nothing, but she grinned at the other girl with appreciation. Trace bethought himself of the old Western axiom, that one good man with a rifle was worth four good men with revolvers. He took the big sporting gun from Johnson, and, thrusting his ray pistol into the front of his shirt where it would be handy, walked purposefully at the next door. He had a feeling about this one.