Stewart shrugged, deciding to let the other wrestle in silence with his phobias, whatever they might be. As for himself, he had his own brand of jitters to worry about. And what made things worse was that he had no idea what was behind them. Not that he hadn't been afraid before. One could hardly put in twelve years with the Bureau of Interstellar Exploration without getting his courage sullied somewhere along the way by a cliff-hanger or two. But, in each of those cases, the menacing factor had been vivid, easily recognizable, something he could put his finger on. The apprehension that lurked in the back of his mind now, however, was something he had never encountered before. Vague to the point of being mysterious, it seemed to be hardly more concrete than a fear of fear itself. But he felt that at any particular moment, if he found the right curtain to draw aside, he would expose a darkened recess filled with horror. Was this dread something that was reaching up from the depths of his phantasmagoric nightmares? Was his subconscious, for some reason, handing up reservations on the acquisition of the Hyades as pearls on the string of galactic expansion? Intuition? Hunch? Whatever it was, he didn't like it. And he cared for it even less now--as he trod the surface of this remote satellite and stared hypnotically ahead at the brilliant stars of the Hyades, well above the horizon. For how could he be certain _this_ wasn't a nightmare and that in the next instant the stella ova wouldn't hatch and hurl their fierce Harpies at him? "Why don't you try the big boy with a few commands?" Mortimer's voice rasped in his earphones. The ship systems officer, pulling up the rear, resembled an overinflated balloon as he gestured at the line of telepuppets through a breach in the ridge. Satisfied with the concealment their present position offered, Stewart flipped on the command transmitter and intoned, "Supervisor to OC. Stabilize and remain where you are." The master robot didn't even break stride. He tried the order again, then repeated it several times as he tuned slightly up and down the band. "It's no use," he said finally. "Either the thing's slipped frequency, or it's not receiving at all." "Carol will spot any new wave length," Randall assured. "What we ought to do," Mortimer proposed impatiently, "is show that thing who's boss." Then Stewart caught the motion in the corner of his eye as the ship systems officer struck out for the marching file of puppets. He intercepted the line near the tail end and tried to force his way in between the Solar Plasma Detector and the Magnetometer so he could close in on the OC. But the SPD kicked out with a stiff pedal pad and sent him sprawling in the path of the Magnetometer, which simply strode over him.