Having failed in space, the refugees took Regal charity as ecologists of the sunken gardens. Dozens of factions were quarantined in cheerless redemption camps, isolated from one another, their lives pared to a grim frugality.

And the visionary Regals made good use of their power. The factions found themselves trapped in the arcane bioaesthetics of Posthumanist philosophy, subverted constantly by Regal broadcasts, Regal teaching, Regal culture. With time even the stubbornest faction would be broken down and digested into the cultural bloodstream of T-K. Faction members would be allowed to leave their redemption camp and travel up the Ladder.

But first they would have to prove themselves. The Patternists had awaited their chance for years. It had come at last in the Ibis Crater competition, an ecological struggle of the factions that would prove the victors' right to Regal status. Six factions had sent their champions to the ancient

Ibis Crater, each one armed with its group's strongest biotechnologies. It would be a war of the sunken gardens, with the Ladder as the prize.

Mirasol's crawler followed a gully through a chaotic terrain of rocky permafrost that had collapsed in karsts and sinkholes. After two hours, the gully ended abruptly. Before Mirasol rose a mountain range of massive slabs and boulders, some with the glassy sheen of impact melt, others scabbed over with lichen.

As the crawler started up the slope, the sun came out, and Mirasol saw the crater's outer rim jigsawed in the green of lichen and the glaring white of snow.

The oxygen readings were rising steadily. Warm, moist air was drooling from within the crater's lip, leaving a spittle of ice. A half-million-ton asteroid from the Rings of Saturn had fallen here at fifteen kilometers a second. But for two centuries rain, creeping glaciers, and lichen had gnawed at the crater's rim, and the wound's raw edges had slumped and scarred.

The crawler worked its way up the striated channel of an empty glacier bed. A cold alpine wind keened down the channel, where flourishing patches of lichen clung to exposed veins of ice.

Some rocks were striped with sediment from the ancient Martian seas, and the impact had peeled them up and thrown them on their backs.

It was winter, the season for pruning the sunken gardens. The treacherous rubble of the crater's rim was cemented with frozen mud. The crawler found the glacier's root and clawed its way up the ice face. The raw slope was striped with winter snow and storm-blown summer dust, stacked in hundreds of red-and-white layers. With the years the stripes had warped and rippled in the glacier's flow.

Mirasol reached the crest. The crawler ran spiderlike along the crater's snowy rim. Below, in a bowl-shaped crater eight kilometers deep, lay a seething ocean of air.

Mirasol stared. Within this gigantic airsump, twenty kilometers across, a broken ring of majestic rain clouds trailed their dark skirts, like duchesses in quadrille, about the ballroom floor of a lens-shaped sea.

Thick forests of green-and-yellow mangroves rimmed the shallow water and had overrun the shattered islands at its center. Pinpoints of brilliant scarlet ibis spattered the trees. A flock of them suddenly spread kitelike wings and took to the air, spreading across the crater in uncounted millions. Mirasol was appalled by the crudity and daring of this ecological concept, its crass and primal vitality.

This was what she had come to destroy. The thought filled her with sadness.

Then she remembered the years she had spent flattering her Regal teachers, collaborating with them in the destruction of her own culture. When the chance at the Ladder came, she had been chosen. She put her sadness away, remembering her ambitions and her rivals.

The history of mankind in space had been a long epic of ambitions and rivalries. From the very first, space colonies had struggled for self-sufficiency and had soon broken their ties with the exhausted Earth. The independent life-support systems had given them the mentality of city- states. Strange ideologies had bloomed in the hothouse atmosphere of the o'neills, and breakaway groups were common.

Space was too vast to police. Pioneer elites burst forth, defying anyone to stop their pursuit of aberrant technologies. Quite suddenly the march of science had become an insane, headlong scramble. New sciences and technologies had shattered whole societies in waves of future shock.

The shattered cultures coalesced into factions, so thoroughly alienated from one another that they were called humanity only for lack of a better term. The Shapers, for instance, had seized control of their own genetics, abandoning mankind in a burst of artificial evolution. Their rivals, the Mechanists, had replaced flesh with advanced prosthetics.

Mirasol's own group, the Patternists, was a breakaway Shaper faction.

The Patternists specialized in cerebral asymmetry. With grossly expanded right-brain hemispheres, they were highly intuitive, given to metaphors, parallels, and sudden cognitive leaps. Their inventive minds and quick, unpredictable genius had given them a competitive edge at first. But with these advantages had come grave weaknesses: autism, fugue states, and paranoia. Patterns grew out of control and became grotesque webs of fantasy.

With these handicaps their colony had faltered. Patternist industries went into decline, outpaced by industrial rivals. Competition had grown much fiercer. The Shaper and Mechanist cartels had turned commercial action into a kind of endemic warfare. The Patternist gamble had failed, and the day came when their entire habitat was bought out from around them by Regal plutocrats. In a way it was a kindness. The Regals were suave and proud of their ability to assimilate refugees and failures.

The Regals themselves had started as dissidents and defectors. Their Posthumanist philosophy had given them the moral power and the bland assurance to dominate and absorb factions from the fringes of humanity. And they had the support of the Investors, who had vast wealth and the secret techniques of star travel.

The crawler's radar alerted Mirasol to the presence of a landcraft from a rival faction. Leaning forward in her pilots couch, she put the craft's image on screen. It was a lumpy sphere, balanced uneasily on four long, spindly legs. Silhouetted against the horizon, it moved with a strange wobbling speed along the opposite lip of the crater, then disappeared down the outward slope.

Mirasol wondered if it had been cheating. She was tempted to try some cheating herself -- to dump a few frozen packets of aerobic bacteria or a few dozen capsules of insect eggs down the slope -- but she feared the orbiting monitors of the T-K supervisors. Too much was at stake -- not only her own career but that of her entire faction, huddled bankrupt and despairing in their cold redemption camp. It was said that T-K's ruler, the posthuman being they called the Lobster King, would himself watch the contest. To fail before his black abstracted gaze would be a horror.

On the crater's outside slope, below her, a second rival craft appeared, lurching and slithering with insane, aggressive grace. The craft's long supple body moved with a sidewinder's looping and coiling, holding aloft a massive shining head, like a faceted mirror ball.

Both rivals were converging on the rendezvous camp, where the six contestants would receive their final briefing from the Regal Adviser. Mirasol hurried forward.

When the camp first flashed into sight on her screen, Mirasol was shocked. The place was huge and absurdly elaborate: a drug dream of paneled geodesics and colored minarets, sprawling in the lichenous desert like an abandoned chandelier. This was a camp for Regals.