As he spoke, he swung the right grapple of the suit in a sweeping arc that caught the robot in the neck and sent it sprawling. But Derec had barely taken three steps when it was back again, clawing at the suit’s emergency panel.

This time Derec reached down and grabbed the robot’s right leg, upending it and dropping it on its back. Catching its ankle with the other grapple, Derec pinched down hard until he heard the sounds of metal crumpling. When he released his grip, the robot’s leg was crippled, the foot frozen at an odd angle.

Derec climbed into the open cab unimpeded. As he backed the carrier away from the wall and turned it toward the ramp, he saw Monitor 5 still lying on the floor where he had left it, vainly trying to repair the damage Derec had done. It’s slitlike scanners followed Derec and the carrier across the chamber.

It was still watching him, its gaze somehow forlorn and somehow accusing, when Derec drove the carrier up through the lock and out onto the surface.

Chapter 7. Friend Or Foe

After his time underground, it seemed strange to have the infinite open sky of space overhead. The sun, a tiny orange disk, hung low in the sky. Barely twenty degrees above the horizon, it cast long shadows into the depressions. The sky was bright with stars, but no planets declared themselves to Derec’s eye.

He did not know how long it would take to make the modifications to the augment. He only knew that the raider ship’s orbit was bringing it closer, and he had to be done before it arrived. He knew too that the robots would be pursuing him in a short-sighted effort to protect him. It was as though the jaws of a vise were closing on him. Somehow he had to squirm away or die.

He only drove far enough over the rugged, frozen terrain to separate himself from the potential target of the complex entrance. Then he parked the carrier half in shadow on a valley floor and started off on foot across the frozen wastes. Though he was sacrificing speed in giving up the carrier, the vehicle almost certainly contained a tracking transponder that would lead the robots right to him.

As soon as he was on foot, he began looking for the right place to hole up while working on the suit. He did not need sunlight for what he had to do, since the augment had its own worklamps. A shadowed hollow, a darkened crevice, a pitch-black ice cave-any of those would hide him without hindering his efforts. But the better hidden he was, the less warning he would have about the approach of the robots or the raiders. There was no having it both ways.

While Derec hiked across the frozen terrain and equivocated, he used the augment’s omnidirectional radio to send a series of distress calls. Derec did not know if the signals would carry over the horizon to the raider, and he feared that they would lead the robots to him. But he had to try, had to give the raiders a chance and a reason to save him.

“Clear channel, code 1. To all ships: pilot marooned, requires pickup. Respond if in range. To all ships-”

Eventually Derec settled on a fissure in an ice cliff that faced back the way he had come. From there, he had a fair view of the terrain, except for what was blocked by the larger crags and mounds. And he had a clear view of the sky from the horizon on the northwest to the horizon on the northeast.

“Diagnostic library,” he said.

The lower half of the bubblelike viewport turned opaque and a list of subsystems appeared on it in bright yellow letters. He scanned down the list quickly.

“Motive systems.”

One of the items near the middle of the list flashed twice, and then the entire list was replaced by another. In the same manner, Derec worked his way through the help screens until the circuit and logic paths of the subcontroller filled the half-display with a maze of fine tracings. Derec studied the system carefully, his lips pursed into a frown.

“Frost,” he muttered finally.

It was as he had feared. The governor was not a physical device that could be readily disconnected. It was a feedback loop in the leg servo circuits. The loop told the suit controller, “Do not allow the force applied by the drivers to exceed a force ofx number of dynes persecond.” Small forces applied quickly were acceptable, as were large forces applied slowly. But large forces applied quickly, which was what he needed, were forbidden.

If he had had more time, there might have been a chance to reprogram the subcontrollers. But under the circumstances, it would have to be radical surgery. Fortunately, augments were designed to be field-repairable, a practice which had saved more than one laborer’s life.

The various “hands” which the augment could use were located in bulging closures on the suit’s thighs. Derec selected an illuminated micromanipulator for the right, and a spotweld laser for the left.

Just then the ground under and around him shook suddenly, bringing a minor avalanche of slow-falling particles down on the crown of the suit. “Clear,” he ordered. The bubble became a window again, revealing to Derec a chilling sight. The attacking spacecraft had climbed above the western horizon. It was still firing randomly, still carving out a path of destruction on the asteroid’s surface. Time was running out.

“Shut down subsystem twenty-four.” That was it: he was committed. With the leg controllers powered down, Derec could no longer walk.

The modifications included burning through three circuit traces and fusing a fourth to a neighboring circuit as a shunt. Accuracy with the tiny laser was absolutely critical. A misfire could destroy enough circuits to cripple the augment permanently.

With the help of the augment’s pointing guide, Derec completed the work on the right leg without mishap. But by the time he was ready to start on the left, the vibrations from the more powerful explosions were more than strong enough to disturb his aim. As he stood trying to outguess the shaking ground, a familiar voice intruded:

“Derec, please listen. Derec, you must stop. This is madness-”

Two hundred meters away on the slope of the mound due north of him was a robot. It was Monitor 5, waving its arms and advancing directly toward where Derec stood. It was walking easily, with no sign of the damage Derec had inflicted on its leg.

In the same glance, Derec saw that the reason the shaking was stronger was that the raider ship was much closer, more nearly overhead than he had expected. Once again he was trapped between the raiders, who would rescue him by killing him, and the robots, who would kill him by rescuing him.

“Go away!” Derec hissed.

“Derec, you must return to the compound. You are in danger here.”

The raider ship seemed to have taken notice of the robot, for the plain between Monitor 5 and the cliff where Derec stood suddenly came under a barrage of pinpoint laser impacts.

These were not the high-intensity weapons which were shaking the ground, and mercifully, the gunners did not seem to be targeting Derec. But the surface in this area was nearly all ice, and volatile. One blast boiled away the top of the mound behind the robot. Another gouged a deep trench between the robot and Derec.

Derec did not think that would stop Monitor 5, and he was right. The robot scrambled down into the trench before the billow of gas could even dissipate, and Derec lost sight of it.

He could not afford to worry about the robot. Setting his jaw determinedly, Derec went back to work on the left subcontroller. Using the body rigidity and autocontrol of the augment to the fullest, he made short work of it. The three unwanted circuits vaporized in tiny puffs of atomic metal. The two parallel traces melted and merged into one.

“Derec!” Monitor 5 called suddenly. “It’s here! In the ice! I’ve found it!”