“Nearly complete,” Suzi pronounced, gliding into view from the far side of the crawler. “Another five minutes of uninterrupted work and the vehicle will be fully functional.”

“That’s right,” Rick confirmed. “That’s quite a 'bot you have there, Hayama. I’m going to have a whole shipload of questions for you when all this is over, but in the meantime…”

“Right,” Hosato responded. “I’ll get out of your way. Oh.” He suddenly realized he was still holding the wad of papers. “Here, Doc, said you should take a look at these.”

The mechanic took the bundle and frowned at it. “What are they?”

“I don’t know,” Hosato admitted. “Doc just said—” Their heads came around with a jerk. Muffled screams, mixed with the unmistakable sound of blaster fire, were coming from the door.

“My God,” Rick gasped'. They’re in the shop.”

“James. Get Sasha into the crawler. That one, the one that’s working. Suzi. Give him a hand.”

Hosato turned to Rick and lowered his voice. “Get this thing fired up and ready to roll. I’ll see if there’s anything we can do.”

Rick nodded and darted toward the controls of the working sand crawler, and Hosato turned toward the door.

The screams were redoubling. Unseen fists were pounding at the door to the garage. In a flash, Hosato realized what was happening. The door opened into the shop, and the panicked people were shoving against it, prevented by their own numbers from getting it open.

With a curse he ran to the door and threw his weight against it. Then he backed up and launched a flying double kick into the door.

The door didn’t budge an inch.

Hammering on the door, he tried shouting Instructions to the people on the other side. Finally he stopped, realizing the futility of his actions. Simultaneously he realized the screams from the shop were dying out, replaced by eerie silence and the sporadic sound of blasters.

He turned and sprinted for the crawler, fighting back the cold, sick feeling in his stomach.

Hanging over Rick’s shoulder, Hosato peered curiously at the piloting viewscreen as the sand crawler jolted its way across the rough terrain.

“How far is it to the Ravensteel complex?” he asked, swaying as the crawler plunged down another gully.

“Not far,” Rick assured him. “I’ve never been there myself, but I know we’re working opposite ends of the same mineral vein. I figure we should be there by morning… noon tomorrow at the latest.”

Hosato squinted skeptically at the viewscreen. “That’s pretty rough terrain out here.”

“Don’t worry. This baby’s built to run over this stuff.”

Rick’s faith in the vehicle seemed to be well-founded. It was like an exaggerated version of a tank — no, tanks had caterpillar treads, and this had huge balloon tires, eight of them, with independent suspension. More like a large version of an armored car. It was short and wide, with the rectangular crew housing perched in the center. Mounted forward of the housing was a pair of large pincer-arms as well as a small forest of lesser tool arms. The arms could be controlled from the driver’s seat with amazing dexterity and strength. The area to the rear of the housing was taken up by a small airlock that gave the operators access to the outside, should the work require the human touch. It was an impressive machine, but it was still a machine.

“Are you sure the main computer can’t take control of this thing?” Hosato asked nervously.

“Impossible,” Rick assured him.

“If you don’t mind my being blunt, that’s what everyone said about the idea of killer robots. Impossible, but it happened anyway.”

Rick sighed. “Look, are you worried about Suzi running amok?”

“No, but—”

“Well, there’s more chance of her being dominated by the computer than there is of this crawler being affected.”

Hosato shot a glance through the low door to the crew area, where James and Suzi were hovering over Sasha.

“Now, I didn’t mean you should get paranoid about Suzi,” Rick chided. “Look, Suzi’s capable of independent action, but she has no capacity for computer direction. And this crawler has no capacity for computer direction, and it isn’t capable of independent action. The only controls for this baby are right here in my hand, so don’t worry.”

Hosato hesitated a moment, but decided the embarrassment of admitting his ignorance was worth the information to be gained. “How does that differ from what happened back at the complex?” he asked.

“The security robots are like most of the robots we use: run by one central computer. They are free-moving, multifunction robots, but the decision-making and function cues were still left in the central computer.”

He stopped talking to concentrate on piloting the vehicle around a rock formation.

“So all the killer robots were being controlled from the central computer?” Hosato prompted, once the obstacle had been cleared.

“That’s right,” Rick confirmed. “Their activities were too complex and unified to be self-directed. The problem isn’t with the individuals units, it’s with the central computer.”

Hosato swore.

“What’s wrong?” his friend asked. “I had a chance to go after the central computer and passed it up. If I could have gotten to it—”

“—you wouldn’t be here,” Rick interrupted. “Sasha could probably tell you more about it than I can, but believe me, that thing’s protected. You don’t just walk up and turn it off. Incidentally, how is she doing back there, anyway?”

“I’ll check,” said Hosato, and ducked back to the crew area.

Sasha was lying on the floor, her eyes open. Her listless thrashing about constantly threatened to displace the blankets they had heaped on her.

“How is she doing?” Hosato asked.

James turned worried eyes up to him. “We’re trying to keep her covered, but she keeps—”

“They’ll burn through!” Sasha moaned suddenly, sitting up. “We need a bigger block. Collapse another twenty feet—”

“It’s all right, Sasha,” Hosato soothed, taking her by her shoulders and easing her back down.

“You don’t understand.” She turned vacant eyes to him. “They’ll burn through. We’ve got to stop them.”

“They’re stopped,” he assured her. “Everything’s all right. Get some rest, now.”

“Hosato?” She blinked at him. “Could you get a doctor. I think my right hand’s hurt. The fingers feel like they’re on fire.”

She tried to raise her right arm to look at it, but Hosato restrained her.

“Just get some rest. Everything will be all right.”

“Hayama. Come up here, quick!”

Hosato was momentarily torn by indecision.

“Take care of her, James,” he said finally, relinquishing his hold to the boy and starting forward.

“We’ve got problems,” Rick announced grimly as Hosato entered the pilot’s booth. “Watch the rear viewscreen there as we hit the top of this next rise.”

Hosato did as he was told. The moon was bright enough to throw shadows as he surveyed the scene in the viewscreen. At first he saw nothing; then something moved in the center of the screen. A blob detached itself from a patch of shadows, then was obscured from sight as their crawler plunged into the next gully.

“What is it?” he asked tensely.

“The central computer’s sent one of the ore scouts after us.”

“What can it do?”

“Well, it’s got an industrial slicer as one of its tools, and an ore crane for another. It can pick us up or cut us apart, depending on its instructions. From what happened back at the complex, my guess is it’ll cut us apart.”

“Hosato!” James called from the back. “Can you give me a hand here?”

“In a minute, James,” Hosato called back.

“Say, I’ve been meaning to ask,” Rick said. “Is it Hayama or Hosato. The kid there keeps—”

“It’s Hosato. Can that thing catch us?”

“It’s faster than we are, but we’re almost out of range of the computer’s control radius.”

“Good.” Hosato sighed.