Once, Frog had been forced to drop a slave. His computer had erred. It had not kept the tracks of his tail slave locked into the path of those ahead. He had howled and cursed like a man who had just lost his first-born baby.

The abandoned section was now a slag-heap landmark far out the Shadowline. Blake respected it as the tacit benchmark delineating the frontier between its own and Frog's territory. Frog made a point of looking it over every trip out.

No dropped slave lasted long Brightside. That old devil sun rendered them down quick. He studied his lost child to remind himself what became of the careless.

His rig had been designed to operate in sustained temperatures which often exceeded 2000° K. Its cooling systems were the most ingenious ever devised. A thick skin of flexible molybdenum/ceramic sponge mounted on a honeycomb-network radiator frame of molybdenum-base alloy shielded the crawler's guts. High-pressure coolants circulated through the skin sponge.

Over the mirrored surface of the skin, when the crawler hit daylight, would lie the first line of protection, the magnetic screens. Ionized gases would circulate beneath them. A molecular sorter would vent a thin stream of the highest energy particles aft. The solar wind would blow the ions over Darkside where they would freeze out and maybe someday ride a crawler Brightside once again.

A crawler in sunlight, when viewed from sunward through the proper filters, looked like a long, low, coruscating comet. The rig itself remained completely concealed by its gaseous chrysalis.

The magnetic screens not only contained the ion shell, they deflected the gouts of charged particles erupting from Blackworld's pre-nova sun.

All that technology and still a tractor got godawful hot inside. Tractor hogs had to encase themselves in life-support suits as bulky and cumbersome as man's first primitive spacesuits.

Frog's heat-exchange systems were energy-expensive, powerful, and supremely effective—and still inadequate against direct sunlight for any extended time. Blackworld's star-sun was just too close and overpoweringly hot.

Frog warmed his comm laser. Only high-energy beams could punch through the solar static. He tripped switches. His screens and heat evacuators powered up. His companion of decades grumbled and gurgled to itself. It was a soothing mix, a homey vibration, the wakening from sleep of an old friend. He felt better when it surrounded him.

In his crawler he was alive, he was real, as much a man as anyone on Blackworld. More. He had beaten Brightside more often than any five men alive.

A finger stabbed the comm board. His beam caressed a peak in the Shadowline, locked on an automatic transponder. "This here's Frog. I'm at the jump-off. Give me a shade crossing, you plastic bastards." He chuckled.

Signals pulsed along laser beams. Somewhere a machine examined his credit balance, made a transfer in favor of Blake Mining and Metals. A green okay flashed across Frog's comm screen.

"Damned right I be okay," he muttered. "Ain't going to get me that easy."

The little man would not pay Blake to load his ionization charge while his old muscles still worked. But he would not skimp on safety Brightside.

In the old days they had had to make the run from the Edge of the World to the Shadowline in sunlight. Frog had done it a thousand times. Then Blake had come up with a way to beat that strait of devil sun. Frog was not shy about using it. He was cheap and independent, but not foolhardy.

The tractor idled, grumbling to itself. Frog watched the sun-seared plain. Slowly, slowly, it darkened. He fed power to his tracks and cooling systems and eased into the shadow of a dust cloud being thrown kilometers high by blowers at the Blake outstation at the foot of the Shadowline. His computer maintained its communion with the Corporation navigator there, studying everything other rigs had reported since its last crossing, continuously reading back data from its own instruments.

The crossing would be a cakewalk. The regular route, highway hard and smooth with use, was open and safe.

Frog's little eyes darted. Banks of screens and lights and gauges surrounded him. He read them as if he were part of the computer himself.

A few screens showed exterior views in directions away from the low sun, the light of which was almost unalterable. The rest showed schematics of information retrieved by laser radar and sonic sensors in his track units. The big round screen directly before him represented a view from zenith of his rig and the terrain for a kilometer around. It was a lively, colorful display. Contour lines were blue. Inherent heats showed up in shades of red. Metal deposits came in green, though here, where the deposits were played out, there was little green to be seen.

The instruments advised him of the health of his slave sections, his reactor status, his gas stores level, and kept close watch on his life-support systems.

Frog's rig was old and relatively simple—yet it was immensely complex. Corporation rigs carried crews of two or three, and backup personnel on longer journeys. But there was not a man alive with whom Frog would have, or could have, stood being sealed in a crawler.

Once certain his rig would take Brightside this one more time, Frog indulged in a grumble. "Should have tacked on to a convoy," he muttered. "Could have prorated the damned shade. Only who the hell has time to wait around till Blake decides to send his suckies out?"

His jointed leviathan grumbled like an earthquake in childbirth. He put on speed till he reached his maximum twelve kilometers per hour. The sonics reached out, listening for the return of ground-sound generated by the crawler's clawing tracks, giving the computer a detailed portrait of nearby terrain conditions. The crossing to the Shadowline was a minimum three-hour run, and with no atmosphere to hold the shadowing dust aloft every second of shade cost. He did not dawdle.

It was another eventless crossing. He hit the end of the Shadowline and instantly messaged Blake to secure shade, then idled down to rest. "Got away with it again, you old sumbitch," he muttered at himself as he leaned back and closed his eyes.

He had to do some hard thinking about this run.

Eight: 3031 AD

Storm placed the clarinet in its case. He faced the creature on his desk, slowly leaned till its forehead touched his own.

His movement was cautious. A ravenshrike could be as worshipful as a puppy one moment, all talons and temper the next. They were terribly sensitive to moods.

Storm never had been attacked by his "pets." Nor had his followers ever betrayed him though sometimes they stretched their loyalties in their devotion.

Storm had weighed the usefulness of ravenshrikes against their unpredictability with care. He had opted for the risk.

Their brains were eidetically retentive for an hour. He could tap that memory telepathically by touching foreheads. Memorization and telepathy seemed to be part of the creatures' shadow adaption.

The ravenshrikes prowled the Fortress constantly. Unaware of their abilities, Storm's people hid nothing from them. The creatures kept him informed more effectively than any system of bugs.

He had acquired them during his meeting with Richard Hawksblood on The Broken Wings. Since, his people had viewed his awareness with almost superstitious awe. He encouraged the reaction. The Legion was an extension of himself, his will in action. He wanted it to move like a part of him.

Aware though he might be, some of his people refused to stop doing the things that made the lizards necessary.

He never feared outright betrayal. His followers owed him their lives. They served with a loyalty so absolute it bordered on the fanatic. But they were wont to do things for his own good.