"There can't be! Nothing at all shows on my board."

  The thing stopped across the sensor ring from Flattery. An auger extension jerked away from its side, reached toward the foam-plugged hole, withdrew.

  "Who's controlling that thing?" Flattery demanded.

  "Not from here," Prudence said. "And I can see both Tim and John. They're not controlling it."

  "You still getting drain on the computer?" Flattery whispered.

  "Yes."

  "Is the... Ox active?" Flattery asked.

  "Only the original circuits," Bickel said. "Through the AAT bypass. The new doubled units haven't been connected."

  "There can't be another robox in that area," Prudence insisted. "We haven't put any of the damn things on automatic. There's nothing showing on my board. The remotes would take a day and a half at least to -"

  "It's right in front of me," Flattery said.

  He watched it, fascinated. A tool arm extended with an empty sensor socket, reached toward the foam-plugged hole, retreated. A claw arm came up next. It probed the foam, drew back with a swiftness that startled Flattery.

  "What's it doing?" Prudence asked.

  "I'm not sure. It seems to be looking over the damage. Its vid-eyes are turned toward the hole. It acts like it can't decide which tool to use."

  "What can't decide?" That was Timberlake, his voice faint over the Com-central relay from the shop.

  "Try fixing the sensor yourself," Bickel said.

  Flattery swallowed in a dry throat. He lifted a feeler with a guide eye from the tool pouch on his own robox, probed into the foam plug looking for the leads from the conduit.

  Instantly, a whiplike extension shot out of the other robox, trapped his arm, jerked it away. The pain in his arm where the thing had clamped on it was sharp and shocking. He dropped the tool, yelled.

  "What's wrong?" Prudence demanded.

  The whiplike extension slowly unwound, released his arm.

  "The thing grabbed me," Flattery said. His voice was shaky with pain and surprise. "It used its circuit probe... grabbed my arm."

  "It won't let you make the repair?" That was Bickel, his voice coming in loud over the helmet system, indicating he'd plugged into the command circuit from the shop.

  "Doesn't look like it," Flattery said. And he wondered: Why doesn't one of us say what this thing has to be? Why're we avoiding the obvious?

  With an abrupt sense of purpose, the other robox reached out a claw arm, lifted the replacement sensor from Flattery's left hand, matched sensor and socket. Another claw arm recovered the feeler guide, fitted it to the connections of its own circuit probe.

  "What's it doing now?" Bickel asked.

  "Making the repair itself," Flattery said.

  The feeler came out of the hole pulling the leads.

  "John, what's showing on your meters?" Prudence asked.

  "A slight pulse from the servo banks," Bickel answered. "Very faint. It's like the cycling echo of a test pulse. Are you still showing current drain in there? I don't have it here."

  "Drain from the mains into the computer. You should be registering it."

  "Negative," Bickel said.

  "It just fitted the new socket and sensor into the hole," Flattery said.

  "It brought the correct spare parts?" Bickel asked.

  "It took the sensor I brought," Flattery said.

  "It just took it from you?" Prudence asked.

  "That's right."

  "Prue, that test pulse is stronger," Bickel said. "Are you sure nothing on your board is doing it?"

  She scanned her console. "Nothing."

  "Job's finished," Flattery said. "What's the big board show, Prue?"

  "Sensor in service," she said. "I can see you... and it."

  "Try touching that new sensor, Raj," Bickel said.

  "The thing damn near took my arm out the last time I tried that," Flattery objected.

  "Use a tool," Bickel said. "Something long. You've got a telescoping radiation probe there."

  Flattery looked into his robox unit, removed the telescoping probe. He extended it to its limit, reached toward the sensor, touched it.

  The whip-arm flashed out of the other robox. There came a jolting shock and Flattery stared wide-eyed at the stump of the probe in his hand. The severed end drifted upward along the tube, tumbling from the force of the blow.

  "Keee-rist!" That was Timberlake, proving they had the shop's screen switched to this circuit and were watching.

  Flattery swallowed, spoke in a muffled voice: "If that'd been my arm..."

  He stared at the other robox. It sat there, quiescent, its vid-eyes pointed toward him.

  We're playing with fire, Flattery thought. We don't know what's guiding that robox. It could be a repair program we've accidentally activated. It could be something the Tin Egg's designers built into the ship.

  "You'd better get out of there, Raj," Prudence said.

  "No, wait!" Bickel said. "Raj, don't move. You hear me?"

  "I hear you," Flattery said. He stared at the robox, realizing the thing could cut him in half with one blow from that whipping circuit probe.

  The sound of distant activity came through the helmet phones to Flattery.

  "I should have the full computer showing here," Bickel said, "but I can't find that damn robox anywhere on my board. There's not even pulse resonance in any of the loops to hint at the source of control."

  "I can't stay out here forever," Flattery whispered.

  "What's showing on the meters, Prue?" Bickel asked.

  "Still getting computer drain... and that pulse."

  "Raj has been outside the shields for sixteen minutes," Timberlake said. "Prue, what's the radiation tolerance level for his area?"

  She crossed the comparison lines against the time gauge on her main board scope, read the difference. "He should be back inside the shield lock within thirty-eight minutes."

  Movement up the tube caught Flattery's attention. The end of the radiation probe. It had reached the top of its energy curve, was beginning to fall back down toward the grav-center in the core of the ship. As the severed end of the tool neared the other robox, the tip of one of its sensor arms - just the tip - turned to track the passage.

  That minimal activity, that watchfulness, filled Flattery with greater dread than if the robox had attacked the length of tool and torn it apart. There was a sense of waiting about the thing - of waiting and gathering information.

  "Raj." It was Bickel's voice.

  "Yes?"

  "Is there any information in the computer - even a hint - that you might destroy it?"

  Did he send me out here to trap me into answering that question? Flattery asked himself. But the fear in Bickel's voice ruled out that suggestion.

  "Why?" Flattery asked.

  Bickel cleared his throat, told about the programmed violence against the cow embryo and the destructive experiment. "It was programmed to fill in the blanks in its information, Raj, and I put no limiting factor on that. The violence proves it'll stop at nothing to maintain its own integrity. If you pose any threat at all..."

  "You're saying it's conscious?" Prue asked.

  "Not the way we're conscious," Bickel said. "Like an animal - aware... and with at least one drive we can recognize: self-preservation."

  "Raj, answer the question," Prudence said.

  She knows the answer, Flattery thought. He could hear the awareness in her voice. Why doesn't she answer it for me?

  "The computer may well have such information in it," Flattery said. And he thought: I'm trapped! I must get back to quarters, destroy this thing... it's already out of hand. But if I move, it'll kill me.

  He stared at the robox. There was the thing that gave the computer mobility - the thousands of special-function utility robox units throughout the ship - even the one under his hands - if it were shifted to automatic and keyed for program control... and if a consciousness directed it. These were what gave the Ox-cum-computer its gonads and ovaries - these and the computer-linked tools.

  "Would... it react with violence if Raj tried to move?" Prudence asked.

  Silence.

  "What about it, Bick?" Timberlake asked.

  "Very likely," Bickel said. "You saw the violence it used when he tried to touch that sensor."

  "What would you do if someone poked a finger in your eye?" Timberlake asked.

  "It's approaching me," Flattery said, and he felt a flicker of pride at how calm his voice sounded.

  "Stay put," Bickel said. "Tim! Take a cutting torch and -"

  "I'm on my way," Timberlake said.

  "Raj... I think your only hope's to play dead... remain absolutely still," Bickel said.

  A sensor tip was in front of Flattery's eyes now and he found himself staring for a second into a baleful red and yellow glow. The tip retracted, and the robox backed off half a meter, clearing the repair unit by a hair.

  "Let go of your own robox," Bickel whispered.

  Flattery saw his own knuckles white with the force of their grip on the robox control bar. He relaxed the hand.

  "Gravity will set you drifting presently back down the tube," Bickel whispered. "Just let it happen. Stay limp."

  The motion was barely perceptible at first.

  "The locks are part of the central system." That was Prue's voice. "What if they don't..."

  She didn't finish the question, but it was obvious she, too, remembered how the rogue sphincter lock had crushed the life out of Anderson.

  Now, Flattery could see he definitely was drifting back. The two robox units receded up the tube. And that sensor tip remained pointed at him.

  The first lock passed his eyes. It had opened!

  But the lock's transparent leaves remained open after his passage and that ambulant robox was following, hesitantly at first, then faster.

  The AAT klaxon blared in Flattery's helmet, transmitted through the open net from Com-central.

  "Oh, Jesus!" That was Prudence.

  "Was the transceiver open?" That was Bickel.

  "The message is already into the system," Prudence said. "We left it on automatic."

  "Tim, where are you?" Bickel asked.

  "At the hub lock," Timberlake said.

  "Take the message, Prue," Bickel said. "Visio."

  Relays clicked as she shunted the AAT to Com-central. Presently, she said: "Short and sweet. Hempstead tells us to cease ignoring communications. We are ordered to turn back and make no mistake about it. Odd choice of words: 'This is an arbitrary turn-back command.'"

  "He knows what he can do with his arbitrary turn-back command," Bickel said.

  At the sound of Prudence's voice, Flattery had gone cold. The chill of ice water gripped his chest. "Arbitrary turn-back command." It was the coded order he had both dreaded and almost longed for - the "kill-ship" command.

  CHAPTER 27

  "You, my creator, would tear me to pieces and triumph; remember that, and tell me why I should pity man more than he pities me? You would not call it murder if you could... destroy my frame, the work of your own hands."

  - Frankenstein's Monster speaks

  WHILE TIMBERLAKE WORKED his way out through the access tubes toward Flattery, Bickel scanned the shop instruments, hunting for a clue to this behavior by the computer system. Every movement of light or dial, every automatic relay adjustment or swing of an instrument needle, sent fear through him. The lights were like eyes staring down at him.

  As much to quiet his own fears as to help Flattery, he began to talk:

  "Raj, have you done anything at all to pose a real threat to the computer system?"

  "Quite the contrary. I've attempted to... work out the emotional program..."

  "To make it care for us?"

  "Yes. But I didn't insert any form of program."

  Prudence intruded: "I think anything you do on this ship goes into the computer system."

  "I agree." That was Bickel. "Specifically, what did you do?"

  "Tried to show... it that I really care about it."

  "That may be all that's keeping you alive right now," Bickel said.

  Once more, Bickel scanned the shop panels. Not a clue there. Nothing!

  Flattery's thoughts kept revolving around that order from Moonbase: Arbitrary turn-back command.

  It had injected ice water into his veins.

  "Kill ship!"

  "Kill ship!"

  It was a refrain chanted in his awareness.

  A deep hypnotic command, he thought.

  But he could not find it in himself to disobey. The rational arguments for this safety fuse were too compelling. The fate of all humankind was more important than the fate of one man... or of one ship.

  Flattery felt his body knotted by frustration. Here he was out beyond the shields of the core. He had been conditioned to accept this order and execute it, sacrificing himself for the protection of the race. At this point, he couldn't muddy his mind with fanaticism. He knew the dangers to the human race from a runaway mechanical consciousness that nobody could...

  A yell escaped him as something grabbed his leg.

  "It's me, Raj."

  Timberlake's voice. It filled Flattery's helmet phones, but he took a moment to accept the identification emotionally. His heart was still hammering as Timberlake pulled him past the next ring of sensors.

  The nemesis robox increased its speed, maintained a distance of about three meters.

  "Shall I burn it?" Timberlake whispered.

  "Do nothing hostile," Flattery said.

  The edge of the hub chamber entered Flattery's field of vision. Timberlake's hand released his ankle. Flattery felt the grating hump as the hatch to the inner lock was opened.

  "In we go," Timberlake said. He gave Flattery a gentle tug as they drifted down into the hub chamber.

  A lock stanchion came in front of Flattery and he grabbed it, feeling the inertial pull as he checked his motion. That following robox had stopped at the tube exit above them, but its sensor tip, remained pointed at them. Timberlake moved in front of him, cutting off the view of the robox. Flattery backed down through the lock's baffle angle, Timberlake following. The hatch was closed. Timberlake dogged it, turned.

  Flattery crossed to the other hatch, breathing easier now that they were behind the shields and with a hatch between them and that robox. He grabbed the hatch dogs, twisted.

  They remained firmly locked.

  He applied more pressure.

  The dogs wouldn't budge.

  "Come on, let's go," Timberlake said. He added his hands to the effort.

  The dogs remained seated as though frozen.

  Flattery and Timberlake looked at each other, their faceplates almost touching. Flattery's hands felt slippery with perspiration inside his gloves. He could smell the stink of fear within his suit.

  "Go... try the other hatch," Flattery said.

  Timberlake nodded, kicked back up to the baffle and the hatch they had just dogged. Flattery could see Timberlake's muscles lift the shoulders of the suit with the effort of trying to reopen the other hatch.

  It was obvious the other hatch also was blocked.

  Timberlake dropped back down beside him, thumbed the command circuit switch beneath his helmet. "John."

  "John's temporarily off the circuit," Prudence said. "You're out of danger... immediate danger, aren't you?"

  In short, clipped sentences, Timberlake reported their situation.

  "Trapped?" she asked. "How could you be?"

  "Something's jammed the hatches," Flattery said. "Why's John off the circuit?"

  "Oh..." Pause. "He left his helmet... down there. He just yanked it off, unplugged, grabbed up a bunch of equipment and headed for quarters."

  "Your sensors! Where do they show him?" Flattery demanded.

  Silence. Then: "In your quarters, Raj. I don't understand."

  "What's this equipment he took?" Timberlake asked.

  "A whole pile of stuff," she said, "mostly from that bin where you were working, Tim, under the middle of the bench."

  In my quarters, Flattery thought. Our "organ of analysis" didn't miss a thing!

  "Tim, your torch," Flattery said. He pointed to the cutting torch on its tool clip at Timberlake's waist.

  Timberlake shook his head. "A minute ago you were saying do nothing hostile."

  "Give me that torch!"

  "No, sir, Raj. You know what's out there jamming that hatch as well as I do. Another robox unit or two or four or fifty. You had the right idea the first time. Let Bickel -"

  "Don't you know what Bickel's doing?" Flattery demanded, not trying to keep the desperation from his voice.

  "Just as well as you do, Raj. I assembled most of that gear in the center bin according to his schematics. It's a field-effect generator synchronized to a shot-effect generator. There's an electroencephalographic feedback unit... a man-amplifier, he calls it."

  "White box - black box," Flattery said. "We've got to stop him."

  "Why?"

  "He'll wreck the computer."

  "Not that computer."

  Bickel has infected him with his cynicism, Flattery thought. "Then he'll kill himself."

  "That's his lookout, but I don't think he will."

  "When that shot-effect hits him, his muscles will break every bone in his body! That's a hideous way to die."

  "Maybe if he were connected directly to the generator," Timberlake said. "But he won't be. He's going to get the shot-effect through that generator's field - attenuated, buffered."

  "Do you know what's in my quarters?" Flattery asked.

  "A snooping device of some kind," Timberlake said. "I've seen the clues on the meters."

  "A field sorter," Flattery said. "It's tuned to the computer, gated for output. If Bickel takes out those gate circuits..."

  "And he will. Now sit down and be quiet. It's our only chance."

  Flattery glared at him. "If Bickel turns that mechanical monster loose it could wipe out the Earth!"

  "Why don't you try ghost stories for a change?" Timberlake asked.

  "I don't have time to tell you the whole story. That monster has to be stopped. You've got to take my word for it."

  "You're nuts," Timberlake said, but Flattery could see that the idea had touched the life-systems engineer's deepest inhibitions.