Twice they sought cover when flying foxes glided over. By this time surely the Supras would have sent their birds to reconnoiter, but neither her nor Seeker's even sharper vision could make out any of the ponderous, wide-winged silhouettes.

  They were watching a vast covey of the diaphanous silvery foxes bank and swoop down the valley currents when Seeker motioned to her. Distant rumblings came, as though the mountains above them rubbed against a coarse sky. The foxes reacted, drawing in their formation like silver leaves assembling a tree.

  Blue striations frenzied the air. The few remaining clouds dissipated in a cyclonic churn.

  Cley said, "What—"

  Sheets of yellow light shot overhead. A wall of sound followed, knocking Cley against Seeker. She found herself facedown among leaves without any memory of getting there.

  All around them the forest was crushed, as though something had trampled it in haste. Deep booms faded slowly.

  An eerie silence settled. Cley got up and inspected the wrenched trees, gagging at fumes from a split stinkbush. Two flying foxes lay side by side, as though mated in death. Their glassy eyes still were open and jerked erratically in their narrow, bony heads.

  "Their brains still struggle," Seeker said. "But in vain."

  "What was that?"

  "Like the assault before on your people?"

  "Yes . . . but this time"—she swept her hand to the horizon of mangled forest—"it smashed everything!"

  "These foxes took the brunt of it for us."

  "Yes, poor things . . ." Her voice trailed off as the animals' bright eyes slowed, dimmed, then closed.

  "It does not know precisely where we are, so it sends generous slabs of electrical energy to do their work."

  Seeker gently folded the two foxes into its palm and made a slow, grave gesture, as if offering them to the sky. When Seeker lowered its claws Cley could not see the foxes and they were not on the ground or anywhere nearby.

  "What—"

  Seeker said crisply, "I judge we should shelter for a while."

  They climbed swiftly up the rough rise to a large stand of the tallest trees Cley had ever seen. Long, fingerlike branches reached far up into the air, hooking over at the very end. She felt exposed by moving to higher ground, closer to the sky that spat death. From here she could see distant banks of purple clouds that roiled with spokes of virulent light. Filaments of orange arced down along long curves.

  "Following the magnetic field of Earth," Seeker said when she pointed them out. "Probing."

  Cley saw why the Supras had sent no searching birds. Far away quick darts of blue and orange appeared over the Library of Life. In her mind she felt a dim sense of frenzied struggle.

  "The talent," she said. Seeker looked quizzically at her. "I can feel . . . emotion." She remembered Seeker's remark, You have emotions, emotions possess you. What must it be like to not feel those surges? Or did Seeker sense something utterly different? "The Supras are fighting . . . worried . . . afraid."

  "The being above keeps them busy while it searches."

  They moved on quickly. Cley wanted to get over the highest peak and work her way along the broad-shouldered mountains toward where she had lived. She had the image of it all in her head from the flight with Alvin and she felt a powerful urge to return to the familiar.

  When she said this Seeker replied flatly, "They would seek you there in time."

  "So? They'll look everywhere."

  "True," Seeker said, and she thought she had won a small point.

  Seeker sniffed the wind and pointed with its twitching nose. "Come this way."

  "Why?" Her home grounds lay the opposite way.

  "You wished to find Ur-humans."

  "My people?"

  "Not yet."

  "Damn it, I want my kind."

  "This way lies your only hope of eventual community."

  "Seeker, you know what I want," she said plaintively.

  "I know what you need."

  She kicked at a rock, feeling frustrated, confused, exhausted. "And what's that?"

  "You need to come this way."

  They moved at a steady trot. Cley had always been a good runner, but Seeker got ahead without showing signs of effort. When she caught up it had stopped beside a very large tree and was sniffing around the roots. Seeker took its time, moving cautiously, and Cley knew enough by now to let it have its way.

  A large bush nearby gave off an aroma of cooked meat, and Cley watched it uneasily. A small mudskipper rat with an enlarged head came foraging by, smart enough to know that Cley and Seeker were usually no threat to it. It caught the meat smell and slowed, tantalized. The bush popped and spear seeds embedded in the rat. It yelped and scampered away. Another victory for the plants; the rat would carry the seed, nurturing it in return for its narcotic sap, until it died. Then a fresh bush would grow from the rat's body.

  She considered catching the rat for meat, and not incidentally for the narcotic, but Seeker said, "Come."

  Somehow it had opened the side of the tree. This was no surprise to Cley, whose people sheltered in the many trees bioteched for just such use. She entered and soon the bark closed upon them, leaving only a wan phosphorescent glow from the walls to guide them. The tree was hollow. There were vertical compartments connected by ramps and clamplike growths all along the walls. Some creature had nearly filled the compartments with large containers, grainy packages of rough cellulose.

  "Storage," was all Seeker would say in answer to her questions. They climbed up through ten compartments nearly filled with stacks of oblong, crusty containers, until they came to a large vault, completely empty, with a wide transparent wall. Cley thumped it and the heavy, waxy stuff gave with a soft resistance. She watched the still trees outside, all stately cylinders pointing up into a sky that flickered with traceries of quick luminescence.

  This place might be safer; she let herself relax slightly. She took out a knife and gouged the wall. A piece came off with some work and tasted surprisingly good. She ate awhile and Seeker took some. Patches on the walls, ceiling and floor were sticky, without apparent scheme. The compartment smelled of resin and damp wood.

  She chanced to glance out the big window as she chewed and that was why she saw it coming.

  Something like a stick poked down through high clouds, swelling as it approached, so that she saw it was enormously long. Its ribbed sinews were knobbed like the vertebrae of a huge spine. Groans and splitting cracks boomed down so loudly that she could hear them here, inside. Curving as it plunged, the great round stalk speared through the sky like an accusing finger. And, as she watched, the very end of it curved further, like a finger beckoning upward.

  "Time to lie down," Seeker said mildly.

  A sonic boom slammed through the forest. She hastily flattened herself on the resilient green floor of the compartment and gazed up through the big window.

  "It's falling on us!" she cried.

  "Its feat is to forever fall and forever recover."

  "It'll smash these—"

  "Lie still."

  She realized that this was the thin, distant movement she had seen on the horizon from Alvin's flyer. Graphite-dark cords wound across the deep mahogany of the huge, trunklike thing. Fingers of ropy vine unfolded from its tip as it plunged straight downward. The vines flung themselves toward the treetops. Some snagged in the branches there.

  A hard thump ran through their tree.

  She just had time to see the thick vines snatch at the branches of neighboring trees, grip, and tighten.

  The broad nub seemed to hang in air, as if contemplating the green skin of the planet below it and selecting what it liked. It drifted eastward for one heartbeat.

  Heavy acceleration pressed her into the soft floor. They were yanked aloft. Popping strain flooded their compartment with creaks and snaps and low groans.

  Out the window she could see a nearby tree speed ahead. Its roots had curled beneath it, dropping brown clods behind. In another tree,
branches sheared off^ where several thick vines had clutched together; it tumbled away to crash into the forest below.

  She could only lie mutely, struggling to breathe, as a flock of tree trunks rose beside them, drawn to the great beckoning finger that now retracted up into the sky with gathering speed. It swept them eastward as trees lashed in air turbulence, as if shaking themselves free of the constraints of dirt and gravity.

  Against the steadily increasing tension the ribbed and polished vines managed to retract. They drew their cargo trees into a snug fitting at the base of the blunt, curving rod.

  "What's . . . it . . ."

  "Pinwheel," Seeker said. "The center rides high in space, and it spins as it orbits. The ends rotate down through the air and kiss the Earth."

  Seeker's calm, melodious voice helped stave off her rising panic. They were tilting as they rose. Cloud banks rushed at them, shrouded the nearby trunks in ghostly white—and shredded away as they shot higher. She glimpsed the underside of the pinwheel itself, where corded bunches of wiry strands held the vines in place.

  "We spin against Earth's pull, but will slip free."

  Seeker's words gave her an image of an enormous rod which slowly dipped down into the planet's air, one tip touching the surface at the same moment that the other end was farthest out in space. Such a vast thing would be far longer than the thickness of Earth's air itself, a creation like a small, slender world unto itself.

  Rolling bass wrenchings strummed through the walls and floor. Her heart thudded painfully and wind whistled in her ears.

  The strain of withstanding the steadily rising acceleration warped the vines. They stretched and twisted but held the long, tubular trees tight to the underside. She saw that the nub was festooned with shrubs and brush. The Pinwheel stretched away into blue-black vistas as the air thinned around them. The wind in their compartment wailed and she sucked in air, fearing that there was a leak.

  But Seeker patted her outstretched hand and she glanced at the great beast. Its eyes were closed as though asleep. This startled her and a long moment passed before she guessed that Seeker could have done this before, that this was not some colossal accident they had blundered into. As if in reply Seeker licked its lips, exposing black gums and pointed yellow teeth.

  Her ears popped. She looked outward again, through the slow buffeting of tree trunks. "Upward" was now tilted away from the darkening bowl of sky, but still along the chestnut-brown length of the Pinwheel, as they rotated with it. Black shrubs dotted the great expanse that dwindled away, gray laminations making the perspective even starker. Cross-struts of cedar-red tied the long strips into an interlocking network that twisted visibly in the howling gale that tore along it.

  Once they smacked into the nearest tree and a branch almost punched through the window, but their tree wrenched aside and the impact slammed against the wall.

  Her ears popped again and her breath came raggedly. Along the great strips of lighter wood, walnut-colored edges rose. They canted, sculpting the wind—and the roaring gale subsided, the twisting and wrenching lessened. Pops and creaks still rang out but she felt a subtle loosening in the coupled structure.

  The last thin haze of atmosphere faded into star-sprinkled black. She felt that an invisible, implacable enemy sat on her chest and would forever, talking to her in a language of wrenching low bass notes. Cold, thin air stung her nostrils but there was enough if she labored to fill her lungs.

  The ample curve of the planet rose serenely at the base of the window as she panted. Its smooth ivory cloud decks seemed near enough to touch . . . but she could not raise her arms.

  Along the tapering length of the Pinwheel, slow, lazy undulations were marching. They came toward her, growing in height. When the first arrived it gave the nub a hard snap and the trees thrashed on their vine-teathers. The turbulence which the entire Pinwheel felt had summed into these waves, which dissipated in the whip-crack at its ends. Tree trunks thumped and battered but their pressure held.

  Seeker licked its lips again without opening its eyes.

  They revolved higher. She could see the complete expanse of the Pinwheel. It curved slightly, tapering away, like an infinite highway unconcerned with the impossibility of surmounting the will of planets. Vines wrapped along it and near the middle a green forest flourished.

  The far end was a needle-thin line. As she watched, its point plunged into the atmosphere. Undulations from this shock raced back toward her. When these reached her the buffetings were mild, for the trees were now tied snugly against the underside of the Pinwheel's nub end.

  Deep, solemn notes beat through the walls. The entire Pinwheel was like a huge instrument strummed by wind and gravity, the waves singing a strange song that sounded through her bones.

  The Pinwheel was now framed against the whole expanse of Earth. Cley still felt strong acceleration into the compartment's floor, but it was lesser now as gravity countered the centrifugal whirl. Their air, too, thickened as the tree's walls exuded a sweet-scented, moist vapor.

  The spectacle of her world, spread out in silent majesty, struck her. They were nearing the top of their ascent, the Pinwheel pointing vertically, as if to bury itself in the heart of the planet.

  The Pinwheel throbbed. She had felt its many adjustments and percussive changes as it struggled against both elements, air and vacuum. Only a short while ago she had thought that the ravenous green, eating at the pale deserts, waged an epic struggle. Now she witnessed an unending whirl of immeasurably greater difficulty.

  And in a glance she knew that the Earth itself and the Pinwheel were two similar systems, brothers of vastly different scales.

  The Pinwheel was like a tree, quite certainly alive and yet 99 percent dead. Trees were spires of dead wood, cellulose used by the ancestors of the living cells that made its bark.

  Earth, too, was a thin skin of verdant life atop a huge bulk of rocks. But far down in the magma were elements of the ancestral hordes which had come before. The slide and smack of whole continents rode on a slippery base of limestone, layers built up from an infinitude of seashell carcasses. All living systems, in the large, were a skin wrapped around the dead.

  "Good-bye," Seeker said, getting up awkwardly. Even its strength was barely equal to the centrifugal thrust.

  "What! You're not leaving?"

  "We both are."

  A loud bang. Cley felt herself falling. She kicked out in her fright and only managed to propel herself into the ceiling. She struck on her neck wrong and painfully rebounded. Her mind kept telling herself she was falling, despite the evidence of her eyes—and then some ancient subsystem of her mind cut in, and she automatically quieted.

  She was not truly falling, except in a sense used by physicists. She was merely weightless, bouncing about the compartment before Seeker's amused yawn.

  "We're free!"

  "For a bit."

  "What?"

  "See ahead."

  Their vines had slipped off. Freed, their tree shot away from the Pinwheel. They went out on a tangent to its great circle of revolution. Already the nub was a shrinking spot on the huge, curved tree that hung between air and space. She had an impression of the Pinwheel dipping its mouth into the rich swamp of Earth's air, drinking its fill alternately from one side of itself and then the other.

  But what kept it going, against the constant drag of those fierce winds? She was sure it had some enormous skill to solve that problem, but there was no sign what that might be.

  She looked out, along the curve of Earth. Ahead was a dark-brown splotch on the star-littered blackness.

  "A friend," Seeker said. "There."

  27

  They rose with surprising speed. The Pinwheel whirled away, its grandiose gyre casting long shadows along its woody length.

  Despite the winds it suffered, bushes clung to its flanks. The upper end, which they had just left, now rotated down toward the coming twilight. Its midpoint was thickest and oval, following a circular orbit a third
of Earth's radius above the surface. At its furthest extension, groaning and popping with the strain, the great log had reached a distance two-thirds of the Earth's radius out into the cold of space.

  They had been flung off at better than thirteen kilometers per second. This was enough to take the trees to other planets, though that was not their destination. They shot ahead of the nub, watching it turn downward with stately resolution, as though gravely bowing to necessity by returning to the planet which held it in bondage.

  Its lot was to be forever the mediator between two great oceans which others would sail in serenity, while it knew only the ceaseless tumult of the air and the biting cold of vacuum.

  Cley watched silently, clinging to one of the sticky patches on the compartment's walls. There was a solemn majesty to the Pinwheel, a remorseless resignation to the dip of its leading arm into the battering winds. She saw the snug pocket where they had been moored show a flare of ivory light—plasma conjured up by the shock of re-entry. Yet the great arm plunged on, momentum's captive, for its next touchdown.

  She saw why it had momentarily hung steady over the forest; at bottom, the rotation nearly canceled the orbital velocity. Craft on such a scale bespoke enormous control, and she asked in a whisper, "Is it intelligent?"

  "Of course," Seeker said. "And quite old."

  "To do that ..."

  "Forever moving, forever going nowhere."

  "What thoughts, what dreams it must have."

  "It is a different form of intelligence from you—neither greater nor lesser."

  "Who made it?"

  "It made itself, in part."

  "How can anything that big . . . ?"

  Seeker spun itself playfully in air, clicking its teeth in a disjointed rhythm. It seemed uninterested in answering her.

  "Alvin and the others made it, right?"

  Seeker yelped in high amusement. "Time is more reliable than intelligence."

  "Somebody planned that thing."

  "Some body? Yes, the body plans—not the mind."

  "Huh? No, I mean—"