Spinning through the dream of time and dust they came, beneath a lake-cold, lake-blue, lake-deep sky, the sun a crashed and burning wreck above the western mountains; the wind a whipper of turning sand devils, chill turquoise wind out of the west, taking wind. They ran on bald tires, they listed on broken springs, their bodies creased, paint faded, windows cracked, exhaust tails black and gray and white, streaming behind them into the northern quarter whence they had been driven this day. And now the pursuing line of vehicles, fingers of fire curving, hooking, above, before them. And they came, stragglers and breakdowns being blasted from bloom to wilt, flash to smolder, ignored by their fleeing fellows ....

Murdock lay upon his belly atop the ridge, regarding the advancing herd through powerful field glasses. In the arroyo to his rear, the Angel of Death-all cream and chrome and bulletproof glass, sporting a laser cannon and two bands of armor-piercing rockets-stood like an exiled mirage glistening in the sun, vibrating, tugging against reality.

It was a country of hills, long ridges, deep canyons toward which they were being driven. Soon they would be faced with a choice. They could pass into the canyon below or enter the one farther to the east. They could also split and take both passages. The results would be the same. Other armed observers were mounted atop other ridges, waiting.

As he watched to see what the choice would be, Murdock's mind roamed back over the previous fifteen years, since the destruction of the Devil Car at the graveyard of the autos. He had, for twenty-five years, devoted his life to the pursuit of the wild ones. In that time he had become the world's foremost authority on the car herds-their habitats, their psychology, their means of maintenance and fueling-learning virtually everything concerning their ways, save for the precise nature of the initial flaw that one fatal year, which had led to the aberrant radio communicable program that spread like a virus among the computerized vehicles. Some, but not all, were susceptible to it, tightening the disease analogy by another twist of the wrench. And some recovered, to be found returned to the garage or parked before the house one morning, battered but back in service, reluctant to recite their doings of days past. For the wild ones killed and raided, turning service stations into fortresses, dealerships into armed camps. The black Caddy had even borne within it the remains of the driver it had monoed long ago.

Murdock could feel the vibrations beneath him. He lowered the glasses, no longer needing them, and stared through the blue wind. After a few moments more he could hear the sound, as well as feel it-over a thousand engines roaring, gears grinding, sounds of scraping and crashing-as the last wild herd rushed to its doom. For a quarter of a century he had sought this day, ever since his brother's death had set him upon the trail. How many cars had he used up? He could no longer remember. And now...

He recalled his days of tracking, stalking, observing, and recording. The patience, the self-control it had required, exercising restraint when what he most desired was the immediate destruction of his quarry. But there had been a benefit in the postponement-this day was the reward, in that it would see the passing of the last of them. Yet the things he remembered had left strange tracks upon the path he had traveled.

As he watched their advance, he recalled the fights for supremacy he had witnessed within the herds he had followed. Often the defeated car would withdraw after it was clear that it was beaten; grill smashed, trunk sprung, lights shattered, body crumpled and leaking. The new leader would then run in wide circles, horn blaring, signal of its victory, its mastery. The defeated one, denied repair from the herd supply, would sometimes trail after the pack, an outcast. Occasionally it would be taken back in if it located something worth raiding. More often, however, it wandered across the Plains, never to be seen mobile again. He had tracked one once, wondering whether it had made its way to some new graveyard of the autos. He was startled to see it suddenly appear atop a mesa, turn toward the face that rose above a deep gorge, grind its gears, rev its engine, and rush forward, to plunge over the edge, crashing, rolling, and burning below.

But he recalled one occasion when the winner would not settle for less than a total victory. The blue sedan had approached the beige one where it sat on a low hillock with four or five parked sports cars. Spinning its wheels, it blared its challenge at several hundred meters' distance, then turned, cutting through a half-circle, and began its approach. The beige began a series of similar maneuvers, wheeling and honking, circling as it answered the challenge. The sports cars hastily withdrew to the sidelines.

They circled each other as they drew nearer, the circle quickly growing smaller. Finally the beige struck, smashing into the blue vehicle's left front fender, both of them spinning and sliding, their engines racing. Then they were apart again, feinting-advancing a brief distance, braking, turning, backing, advancing.

The second engagement clipped off the blue vehicle's left rear taillight and tore loose its rear bumper. Yet it recovered rapidly, turned, and struck the beige broadside, partly caving it in. Immediately it backed off and struck again before the other had completely recovered. The beige tore loose, and spun away in reverse. It knew all the tricks, but the other kept rushing in, coming faster now, striking and withdrawing. Loud rattling noises were coming from the beige, but it continued its circling, its feinting, the sunlight through the risen dust giving it a burnished look, as of very old gold. Its next rush creased the right side of the blue vehicle. It sounded its horn as it pursued it and commenced an outward turn.

The blue car was already moving in that direction, however, gravel spewing from beneath its rear wheels, horn. blasting steadily. It leaped forward and again struck the beige upon the same side. As it backed off, the beige turned to flee, its horn suddenly silent.

The blue car hesitated only a moment, then sped after it, crashing into its rear end. The beige pulled away, leaking oil, doors rattling. But the blue car pursued it and struck again. It moved on, but the blue swerved, ran through a small arc, and hit it yet again upon the same side it had earlier. This time the beige was halted by the, blow, steam emerging from beneath its hood; this time, as the blue car drew back, it was unable to flee. Rushing forward, the blue struck it once more upon the badly damaged left side. The impact lifted it from the ground, turning it over onto the slope falling away sharply to its right. It rolled sideways, tumbling and bouncing, to be brought up with a crash upon its side. Moments later its fuel tank exploded.

The blue car had halted, facing downhill. It ran up an antenna from which half a dozen spinning sensors unfurled, a fairy totem pole shimmering in the fume-filled air. After a time it retracted the sensors and withdrew the aerial. It gave one loud blare of the horn then and moved away to round up the sports cars.

Murdock remembered. He put his glasses in their case as the herd neared the turning point. He could distinguish individual members now, unassisted. They were a sorrylooking lot. Seeing them, he recalled the points of the best that he had come across over the years. When their supplies of parts had been larger, they had used their external manipulators to modify themselves into some magnificent and lethal forms. Kilo for kilo, the wild ones had become superior to anything turned out in the normal course of production.