by Ian Stewart
The wheeler was waiting in the airlock, metallic coat shining with reflections of the room's bright lights. It extended its frill of vanes, rolled forward until the lip of the inner door threatened to impede its progress; then—quietly and without missing a beat—it rose a foot off the ground and continued its forward progress on antigravity instead of wheels. Its body became suffused with multicolored light and slow sparks.
The wheels kept revolving.
The inner door closed behind it with a rasping thud that seemed primitive in comparison. The silence stretched to the breaking point.
Sir Charles realized that every face was looking at him. Hope, shock, fear . . . emotions were mixed and running high. Someone had to restore a semblance of normality.
"What are you all gawping at?" He stood up and took a few paces toward the now-stationary wheeler as it hovered enigmatically in midair. "You've all seen a functioning wheeler before!" He took a deep breath. "It's not going to blow up in our faces! It's what we came here to accomplish. Contact! It just so happens that"—he found he had to stop and swallow before his voice dried up completely—"the wheelers have made contact with us, instead of the other way 'round."
Feeling a complete fool, he took another couple of steps toward the alien machine, pulse racing, lips dry, nerves taut. The wheeler swivelled slightly, so that its "headlights" were facing him. "Er ..." Sir Charles began. Then, mostly for the benefit of the humans present: "What else can I say? I don't expect you to understand a word, but I hope that somebody will hear and understand that I am trying to communicate." His voice was wavering with emotion. He felt impossibly elated and totally stupid at the same time. W cameras were recording this, for transmission to Earth's teeming billions. This would be fame indeed, and a vindication of his strategy. Something simple yet melodramatic was in order. Slogan politics.
"In the name of the people of planet Earth: greetings!" He felt a complete fool.
The wheeler showed no sign of having heard. It continued to hover a foot off the ground, headlights still staring at Sir Charles's knees, its body glowing.
It seemed to be waiting for something.
11
Secondhome, 1945th Continuity
Within the fibrous body of one of the oldest and largest cities on Secondhome, in a chamber grown specially for the purpose, the Elders of the Conclave assembled and chose to become One.
The ancient blimps floated, bobbing ponderously in the gentle currents of warm air that seeped into the chamber, maintaining it at a pleasant temperature comfortably above the melting point of ammonia.
They were huge, flabby, and very, very old.
Blimps resembled half-inflated weather balloons. At the top was a domed gasbag with pliant, leathery skin. Along the dome's equator was one of two main sensory organs—a ring of six sound-sensitive patches, placed alternately above and below the midline, which together synthesized a three-dimensional image of the blimp's immediate surroundings. A little farther down was the other main sensory organ: six pairs of retractable eyes, embedded in the skin like studs on a leather-upholstered sofa. Twin mouths, stacked one above the other, formed rubber-lipped slits in the thick skin: these mouths were for generating sound, not for feeding. The outside of the creature's lower body consisted of manipulative appendages—six flattish, hollow, rubbery tubes. Each tube ended in a sixfold ring of thinner tubes, whose tips in turn could separate into six wedge-shaped stubs for fine manipulation. At the center of each such fractal trunk was a sphincter through which the creature could ingest solid, liquid, or gaseous food. The sixfold cascade of stomachs, the trifoliate brain, and various other organs hung inside the ring of trunks, below the main gasbag. A short tube for excretion poked out at an angle, oddly off-center.
If the city builders were strange, their cities were stranger. Somewhere in their distant past the blimps had discovered that the component cells of the foam slabs could be persuaded to grow into virtually any shape by applying thin coatings of suitable hormones. Because the resulting structures, like the slabs, were neutrally buoyant, their forms were limited more by imagination than by physics. The main constraint, in fact, was Secondhome's weather. Even at those depths, Secondhome suffered perpetual storms, with intense superbolts of lightning and high winds. The slab material was rigid enough to make permanent structures, yet flexible enough to bend with the wind. Even so, any structure that was long, thin, and insufficiently supported was always in danger of tearing loose, or damaging nearby parts of the city when it flapped in the hurricane-force breezes.
Viewed from above, a city resembled a cross between a panful of scrambled eggs and a coral reef. Close up, it was an intricate mass of tunnels, caves, huge open arenas, buildings that thrust skyward like squat trees with impossibly thick trunks, helical tubes, soft-edged pyramids, domes, bulbous sprouting fans, trailing lines of capsules like strings of fat sausages—all draped with webbing made from a netlike porous membrane, which improved structural integrity. And everywhere there were blisterponds—newly grown, mature, dilapidated, abandoned. These were lenticular voids enclosed by a retractable fibrous sheath. The blimps placed immense value on their blisterponds. They used them to hold stocks of preserved foodstuffs from the planets denser depths for their long estivations, for temporary shelter, and for comfort. Every blimp possessed a personal blisterpond and tended it with infinite care. A stock of spare blisterponds was maintained for occasional newcomers, especially juveniles recovering from the attentions of the sculptor-surgeons.
Motile Eye-Threads of the Mesmerizing Curtailment could never enter the Chamber of the Conclave without remembering when it had first been engineered—a radical new fashion in hormonal architecture that involved locating a natural cyst beneath the city's tough upper skin, then painting its damp surfaces with layer upon layer of wilting hormone so that the dying cells peeled off in dry flakes to be sucked up by sweeper symbiauts. The difficult part, achieved after several celebrated failures, was to do this while maintaining a hard shell that could support the stresses of the tissues above, and to equalize pressures with the outside air so that the growing cyst would neither collapse nor burst during one of the city's periodic changes in altitude.
Broken Tendril of the Imagined Obliquity had won a prize for her work, he recalled. Tragically, Tendril had died in a construction accident—a mere fifteen million years ago, he still remembered it clearly—when an overambitious complex of raked tower-pools collapsed under an accumulation of methane snow in a sudden cyclonic coldstorm. It had been Tendril's own fault— she should have known better than to permit her city to approach so close to the Whirl—but the views of spinning vortex clouds were spectacular in those regions, and Tendril always had a soft spot for visual beauty . . .
As he remembered her, so did the other Elders of the Conclave; and when their collective mind fragmented once more into mere individuality, they would remember remembering her. Which is different from true memory, of course.
The Conclave met to a schedule that had run unchanged, save by dire emergency, for thirty million years. It was not exactly a schedule, because its most important feature was the state of estivation of its pool of "chairmen." No chair, no men, but the description is apt, for back in the lost evolutionary fog of Deep Time, a species of proto-blimp on the lost planet now referred to as Firsthome inadvertently evolved the committee. They developed a kind of hive mentality in which each member retained a degree of individuality, yet decisions could be arrived at collectively through a process of bureaubonding, of which the individuals were not consciously aware. This quasi-telepathic abihty was a by-product of the quantum chromody-namics of their mental processes: they could choose to broadcast their thoughts as a spray of squark wavepackets. The process was voluntary: a blimp's mind could not be read unless it chose to make its thoughts available. The effect was also very short range, because nonlinearities quickly dispersed the wavepackets.
Following tradition, Eye-Threads—for so he was colloquially known when no other
with the same somatonymic was present—opened the proceedings by declaiming aloud, in speech mode, the Standing Agenda. The process was agonizingly slow, for there was much business to transact; it was also unnecessary, since every Elder could recite the Standing Agenda by heart. But they all loved its ponderous, rolling tones, and to them it was pure poetry, not agony.
A typical Conclave lasted for two hundred and seventy Secondhome days—roughly three and a half terrestrial months. To individual blimps this was the merest instant, but the group mind could make most decisions surprisingly rapidly. While the members of the Conclave were bureaubonded, all could see how well judged the traditional Period of Conclave was. When once more separated, however, many of them deplored the shortness of the timetable and their consequent inability to consider any matter in depth. They could remember being involved in making decisions, and even what many of those decisions were, but they could seldom reconstruct the reasoning behind the decisions once the bureaubond had been dissolved. It could be very frustrating at times, knowing that you had approved a collective decision that now seemed ridiculous, but that was one of the prices you had to pay to be an Elder.
You got used to it.
The blimps were not the only alien creatures on Secondhome. They had brought many other organisms with them from Firsthome; there were remnants of Secondhome's indigenous creatures; above all, there were creatures of a very different kind, which had evolved as a symbiotic by-product of the blimp ecology. At an early stage of the blimps' evolution on Firsthome, their hydrogen had been obtained through a biological form of electrolysis, released from enclosed droplets of mineral-bearing fluid. This electrolytic action also deposited layers of unwanted metals. At first these metals had merely been ejected as waste, but as the aggregated cells became ever more complex, a new solution to the problem of waste disposal emerged—the co-evolution of a parallel ecology of metallic biomachines. These "symbiauts" had no genetic material of their own, but increasingly large tracts of the blimps' genome became devoted to the processes of offcasting: the production of useful symbiauts. The symbiauts paid their evolutionary dues, and incidentally kept themselves viable, by performing increasingly complex tasks that enhanced the lives of the blimps. At first they provided new and more efficient ways to store energy, but they quickly diversified into locomotion, weaponry, defense, camouflage, construction, food processing, communication, surface and interplanetary transport—even entertainment. Metal ceased to be waste and became a vital resource.
One of the big problems about settling on Secondhome had been that its atmosphere contained only tiny proportions of metal atoms, but it was a big atmosphere and the metals were concentrated and recycled by biological action. There were significant quantities of germanium, essential for symbiaut memory banks, in the form of gaseous germane—germanium tetrahy-dride. Ions of sodium, potassium, and magnesium diffused into the planets upper atmosphere from the plasma torus that joined it to Fivemoon. The blimps had also brought stockpiles of metal from Firsthome. Some was banked deep inside the cities, but the bulk was deposited in orbit around the gas giant. Interplanetary transpauts could take miner symbiauts out there to retrieve it, as necessary.
Because the slabs were flat on top, back on Firsthome before the blimps had invented the art of hormone-crafting and lived in crude city-burrows, most symbiauts had evolved wheels. Now, many still retained them, and at every level of the city there were networks of roadlike wheelways. Although the symbiauts had eventually evolved antigravity, wheeled motion required less effort and had become the default.
Eye-Threads's sonorous voice echoed around the chamber. It was shaped like a flattened ovoid, and the blimps entered it through the roof, by way of an elaborately decorated driftshaft. There was a separate antigravity dropshaft for the attendant symbiauts, to save them the effort of using their own gravipulsors. It was decorated in the grand style, simulated Late Obsessive from the 811th Continuity, so that the predominant element was the demiconoid. To earthly eyes the effect would have appeared akin to an inside out wedding cake built from a hundred hues of mud. Toward one end of the ovoid there was a sunken dais, shaped like an irregular heptagon with a flat rim surrounding a shallow depression. Here the Elders had gathered, according to tradition, while ever-busy symbiauts thronged the rim, coming and going along a network of suspended platforms linked by elevauts. The attendants provided grooming, food and drink, mild narcotic stimuli, and personal entertainments; they brought and accepted messages, and reminded the Elders of the Nine Thousand Forms of Protocol and the Accepted Order of Proceedings. A battery of memauts—specialized symbiauts which possessed huge quantities of microcircuit memory—recorded all deliberations and decisions, for symbiauts were sensitive to the same squark radiation as the blimps themselves.
If a city died—from lack of food, or disease, or any other cause—its inhabitants would have to locate an immature cityling and transfer to it—a huge effort that resulted in cramped quarters for many generations. Blimps took good care of their cities. Secondhome boasted nearly a million of them, and each of them had been grown on a base of neutrally buoyant living foam, made from living bubbles a few microns across—biological cells with their own genetics and their own specialist organelles. Prominent among the latter were levispheres, tiny membrane-walled bubbles of almost pure gaseous hydrogen which provided lift in the denser hydrogen-helium mixture of the planet's troposphere—one part helium to five parts hydrogen, roughly twice as dense as hydrogen alone. The cells' production of levispheres was sensitive to pressure differences, and a feedback mechanism had evolved that maintained neutral buoyancy.
The city's metabolism warmed the gas, which generated additional lift as it expanded to equalize pressures. A city was a hybrid, part hydrogen balloon, part hot-air balloon. Huge cooling-vanes trailed beneath the city like a keel, radiating surplus heat, fed by circulating coolant that flowed through a network of veins and arteries, pumped by thousands of local heartlike organs. The foam was a vast colony-creature, which had grown over the millennia until it formed an irregular slab a hundred miles long, ten miles wide, and between one and five miles thick. The slab's upper surface, unadorned, would have been flat. Instead, it had been decorated with the superstructure of the city, coaxed from the firm foundation by the chemical attentions of countless generations of blimps. Tunnels and shafts penetrated deep into the city's living tissues, forming a labyrinth of cavernous chambers.
The city's lower surface was a seemingly endless jungle of suspended tendrils surrounding the cooling-vanes, like the myriad tentacles of a Portuguese man-o'-war. Near the edges of the foam slab the tendrils spread sideways to form a monstrous fringemass, which rippled unpredictably in the turbulent Secondhome weather. Farther in, the tendrils were closer to the vertical—becoming longer as their roots neared the slab's central vanes, where its component cells were oldest. Here many tendrils had grown to a length of more than fifty miles. Like the rest of the slab, they were neutrally buoyant, and they had yet to reach their full length.
Around the city swarmed a fine haze of aeroplankton, trillions upon trillions of airborne microorganisms. Each of the slab's tendrils was a specialist trap, evolved to lure specific categories of aeroplankton into more or less elaborate forms of suicide. Some tendrils were sticky. Some fired tiny harpoons toward any source of pheromones to which they were sensitive, and reeled in their catch. Some sucked the heavy atmosphere through cavernous baleenlike filters, while tiny scuttlepods clambered over the fibrous drapery and scraped the catch into irised pouches. In return, a ring of enlarged pores around the lips of the pouches oozed an energy-rich sludge, at which the scuttlepods occasionally licked. Other tendrils generated focused pulses of ultrasound, spread chemical lures, filled the surrounding air with tiny semi-autonomous homing webs, or merely waited for prey to blunder into sprung traps.
Once they had secured their prey, however, nearly all of the tendrils treated it in the same manner. First they dissolved its membranes, releasi
ng the embedded levispheres. Most of these escaped into the atmosphere, where they were degraded by heat and pressure, recycling their hydrogen. The rest were used to fine-tune the local neutral buoyancy. The nutrients that had been released when the membranes dissolved were transported through a fractal tree of molecular nanotubes, dragged upward by stepper viruses which climbed the nanotubes like a mountaineer in a rock chimney. As the viruses climbed higher, the trickle of rising nutrients became a torrent, then a flood, pouring into clusters of slimy spherical sacs that festooned the slab's underside, dangling between the swelling roots of the suspended tendrils. Here the stepper viruses were released, falling through Secondhome's atmosphere in an infinitely slow drizzle of genetic add-ons, to reinfect any tendrils that they chanced to encounter.
The blimps that lived on the slab's upper surface were seldom conscious of the aeroplanktonic Armageddon that went on just below them, as it had done every day for a third of a billion years. Mostly they just accepted one of its minor side effects, the creation of enormous floating platforms: the bedrock, so to speak, upon which their civilization was founded. Only when a city slab became sick were the veterinary squadrons and air gardeners activated, to descend into the hidden depths and effect whatever cures were necessary.
The blimps had evolved in a hydrogen ecology. They, like many lesser creatures of their world, were balloons: they, alone, were thinking balloons. Some balloonist organisms, like the slab, were made from microscopic levisphere-rich cells. Others had larger hydrogen-filled organs, fulfilling much the same function as a terrestrial fish's swim bladder—to maintain neutral buoyancy. Most also used the hot-air principle to enhance their buoyancy; many employed that alone. The city builders and their ilk did not so much fly as swim in the surging Secondhome air.