Collected Short Fiction, page 765
Dropped off the skywire, the descender was soon lost in the bluish murk. Its radio signals faded and went out. It could never return because the atmosphere at the bottom of the skywire was too thin to float it, but he hoped it would get back into radio range.
Waiting for that took a long time. Chou monitored the spot where it had vanished, listening for anything. Seven months went by—Terran months; the colonists still measured time by the clocks and calendars they had brought from old Earth. His hopes were fading before the transponders picked it up again.
Random drift had carried it five thousand kilometers east. It was still invisible, floating below a layer of ice-crystal clouds. Even its radio signals were muffled and dimmed, garbling its recorded data. Chou was able to pick up fragments of only a few transmissions before it went abruptly silent.
Searching for it with the satellite’s telescopes, his assistants never found it, but they did report a perplexing observation. At the moment it stopped sending, they saw a vast dark shadow that leaped and whirled and vanished again, disturbing the thin ice-cloud.
“What?” Chou wrote that unanswerable question in his notebook, and underlined the words. “What could it have been? I suppose one might imagine a creature curious enough to follow our descender up out of the depths and large enough to swallow it. But what manner of thing could digest that kwanlon shell?”
Many of the recorded radar and lidar and kinescope images had been lost, but he kept his computers reprocessing the intact fragments and piecing them together until he had a record of the voyage complete enough to keep him more than ever tantalized.
The descender had dropped fast at first. The green dusk faded into utter blackness, lit only by the stroboscopic flash of the searchlights. Savage near the surface, the winds grew sluggish, then violent again in convective storms where blue lightning burned and thunder jarred the instruments.
As the atmosphere thickened, the descender settled ever more slowly through ammoniac rain that evaporated again as temperatures rose. It sank through ice-crystal clouds, through a level of great, slow-floating flakes of something the telemetry failed to identify. Now and then, there were radar images of something stranger: vague and distant shapes too far for the camera and lidar lenses to reach, too far even for the radar to pick up any clear detail.
Chemical clouds? Density contrasts, perhaps due to temperature anomalies in convective columns? Or fleeting glimpses of something—something unknown and maybe unknowable? Wondering again what had silenced the first descender, Chou ran those tapes again and again. He could never be sure.
External pressures grew enormous, overloading the heat pumps that cooled the kwanlon shell. Internal temperatures climbed so high that the shell had to be driven to total reflectivity, opened for only the briefest flashes of incoming radiation.
Only a handful were left alive when Sam Kwan-Liang arrived with another fugitive crew. He was a renegade plastics engineer in flight from charges of treasonable conspiracy against the Sun Tycoons. False accusations, so he claimed, fabricated to protect the Company monopoly on kwanlon.
That was a nearly miraculous stuff, invented and perfected by earlier generations of his own family. A synthetic mix of carbon and silicon, kwanlon could be spun into monomolecular filaments approaching quantum limits of tensile strength. Skywires fabricated of it had linked geosynchronous satellites with the surface of Earth. Lifting cargo to space stations and dropping the gathered wealth of space back to the mother planet, it had woven the vital fabric of the Company.
Its uses were endless. Kwanlon bubbles could form immense and safe enclosures for space habitats. Properly doped, it became superconducting. Wound into the magnetic elements of fusion engines and fusion drives, it generated energy and drove spacecraft.
Kwan-Liang brought skills to make and spin and dope and anneal it, skills that meant life for the dying colony. The dusty snows of Nereid were rich enough in nitrogen and oxygen to make atmospheres for new orbital habitants, rich enough in everything to feed new hydroponic gardens.
Leading the way back down toward Neptune, Kwan-Liang built Triton’s first geosynchronous satellite and dropped a skywire to its impact-pitted snows. It had cooled too fast for crustal tectonics to deposit heavy metals near the surface, but a crew began drilling through the silicate mantle toward the richer ores they hoped to find somewhere beneath.
At first that pit went fast, but the metal-poor crust proved unexpectedly thick. The waste rock grew too difficult to lift, and temperatures increased until the walls of the shift began to crack and creep. Men and women died, but at last they began striking workable ores. Year after year, the stubborn survivors kept inventing new equipment, kept on digging.
More refugees arrived. Still dreading the ruthless reach of the Sun Tycoons, the colonists tried to keep themselves concealed. Most seemed happy enough with their hard frontier, sufficiently absorbed in coping with its penalties and promises, yet there were malcontents.
The younger generation, those who had never felt the cruel reins of Company law, had always been entranced by the stray radio and TV signals picked up from toward the Sun. Dreaming of the richer and more varied ways of life they imagined on the older worlds, a few rebelled. Seizing a survey ship, they took off for Earth.
Alarmed, the settlers put sentry satellites into orbit and dug fortresses into the ice cliffs of Nereid, but the final outcome was not entirely bad. One who went back had been Kwan Gunnarson, a nephew of Sam Kwan-Liang and a grandson of the first pioneer. Welcomed by the Tycoon as a willing informer, he was allowed to earn science degrees at Kwan Tech. Recruited later as a secret agent for the Company, he infiltrated another band of dissidents and returned with them to Neptune on a hijacked space freighter.
At first only pretending to repent, this renegade Gunnarson set up a secret radio station to carry his reports back to the Company. He married a colonial girl and set up a new observatory in geosynchronous orbit around Neptune itself. That project may have been planned only as a cover for his spy work, but it soon began to absorb him completely.
Neptune’s dim and hazy face was still a hostile mystery. An unending sea of dull-blue gases, roiled with never-ending storms. What lay beneath it was all unknown, but the traitor’s calculations had convinced him that there ought to be some sort of solid center, probably fractionated into a surface of mixed ices over a rock-and-metal core.
His only data came from the thin and frigid winds he could observe, but even in them he found enough to fascinate him. Flow patterns changed in unexpected ways, and the planet radiated more energy than it received from the Sun.
“I dreamed last night,” he wrote in a private diary. “Dreamed I had an answer to the riddle of the planet. An answer I can’t forget, though this morning it seems unbelievable. It’s a notion common prudence may never let me publish, but I want to record it here, to be examined again when my mood has cooled.
“In the dream, I discovered that those perplexing disturbances in the wind flow are caused by moving objects. A notion nobody else is likely to care for. This morning, anchored to my desk here in the free-fall lab with the planet’s cold blue-green gloom shining up around me through the ports in the floor, I can’t quite imagine anything big enough to cause those enormous eddies, solid enough to hold its shape in these hurricanes, yet light enough to climb to the levels we can observe. The answer dazed me when I found it in the dream, and it still rocks my sanity.
“In the dream, I found evidence that they were alive.
“Awake, I can’t see any sane hypothesis to explain how that could be. What could be their cycle of life? Where their energy source? Perhaps that mysterious flow of excess energy out of the core? Nothing I think of makes much sense.
“Certainly, no such creature could have anything in common with anything we know. Nothing evolved from anything like Terran protoplasm could survive an instant in these storms of noxious gases. Yet I can’t help reflecting that even back on old Earth, thriving life was found in toxic jets of superheated water ejected from undersea volcanoes.
“All I can do is keep a careful silence. I suppose I shouldn’t even think about it, but the riddle will always tease me.”
More new fugitives kept on coming, slipping past Company bans with outlawed knowledge and updated technologies. Some of them joined the observatory staff to drop a skywire from it into the surface turbulence of Neptune itself.
Used at first only to support telemetric gear, that experimental line was soon redesigned to tap the planet’s gravity for energy. With field effects reversed, the same motor cables that lifted elevator cars became dynamos. Waste mass, loaded into magnetic buckets sliding down the motor line, transformed gravitic force into power for transmission out across space to all the orbital habitats, to those miners still toiling toward the heart of Triton, even to far Nereid.
New explorers, impatient with the slow progress of the pit, had gone out to claim another source of ores, a small asteroid somehow tossed from its origin in the metal-rich regions nearer the Sun. They lost it to a Company fleet. A new Tycoon dispatched a cruiser squadron to tame the colonists and restore the kwanlon monopoly. Unarmed, the salvage crew had to surrender themselves and their prize.
Yet, tested to such extremes, the descender endured everything. It passed the one-thousand-kilometer level. Still intact, it fell through the two-thousand-kilometer level. Instruments open for only milliseconds by then, it passed twenty-five hundred kilometers. At two thousand eight hundred and sixty, the radio altimeters indicated a solid surface still thirty kilometers below.
A surface!
Chou felt the jolt of that, almost as if he had been aboard the robot craft. His own computer models had given him conflicting pictures of Neptune’s interior. Summing them up, he had come to expect a semiliquid transition zone between gaseous and solid states, possibly scattered with floating bergs of crystal hydrogen. Certainly nothing like these perplexing images.
Any sort of surface should have been level, so he had thought, smoothed with layers of chemical snows precipitated from above. Amazingly, the few recorded images showed a seemingly endless slope littered with broken boulders, some of them enormous.
Two kilometers above them, the pilot computer had released ballast to check the descent. The atmosphere here was too dense for any rapid motion, but a sluggish current carried the descender slowly up that boulder-slope. With the heat pumps at the brink of failure, the lenses had been opened for only half a dozen more exposures.
The briefest possible flashes, those traced the probe’s drift across a towering upthrust from which the boulders must have somehow been shattered. Beyond it, the surface dropped sharply toward a floor so distant that haze obscured it.
One revealing frame had caught a mountain-sized fragment at the brink of the pit in startling detail. It looked crystalline, seemingly transparent, illuminated with its own prismatic reflections of the strobes.
At that point, the computer had cut the mission short. It jettisoned a series of experiments designed to drive test holes for crust specimens and dropped all the remaining ballast to climb back to safer levels.
The final radar image, the most perplexing of all, showed something looming out of the dark ahead of the drifting descender, something almost on its own level and many kilometers above that far-off floor. Chou spent many hours trying to coax any definite detail out of the haze-veiled shape and came to no firm conclusion.
“Only a cloud?” He wrote that question into his notes. “Perhaps.” He underlined perhaps. “At that level, however, under the recorded conditions of temperature and pressure and chemistry, I can’t imagine what would condense into a cloud.
“Something—I shrink again from what lunatic dream—something alive?
“It must have been twenty kilometers away, drifting at the extreme limit of the prevailing radar range. It was huge! Most of it must have been too far for the beam to reach it. The image is too badly blurred even to hint at wings or limbs—if the thing was a being with wings or limbs or any other comprehensible organ.
“I can’t imagine—”
The entry closes with that phrase, bold-stroked for emphasis. Later notes record months of effort to enhance and interpret that fragmentary record. Studying the images of those unexpected crystal masses, he recalled an old conjecture about the heart of Neptune, the notion that its core might be armored in diamond.
Diamond!
Ancient astronomers had speculated that most of the carbon compounds in the native cosmic mix that formed the planet must have precipitated out and settled in a thick layer around a mostly metallic core. Baked clean of all volatiles as temperatures and pressures rose, the carbon should have fused and tinally crystallized into a solid shell.
A romantic daydream? The evidence for it, that image of a whole mountain range of shining diamond, was too dazzling to be denied. It must have crystallized far below, he had to suppose; some volcanic cataclysm of the planet’s youth must have thrown these shimmering fragments up through a crust of lighter stuff.
A world-sized diamond!
The vision kindled a fever in him. Men on the home worlds had enslaved themselves and murdered one another for diamonds small enough to swallow. Here, near enough for the robot almost to touch, was treasure that could change the fortunes of the colony and alter human history in ways he hardly dared imagine.
If it could be recovered—
That problem baffled him. His own resources were used up. Any recovery effort would take a far more sophisticated device than his lost descender. He was wary of asking for help. Even a rumor of his discovery would surely bring Company fleets to snuff out precarious freedoms and claim his diamond strike for the Sun Tycoons.
Yet he resolved to try. He hid most of his recordings, enciphered the best computer transmissions, and applied for a Terran visa. The next ship to call took him home. He had two children there, born to a wife who refused to share his exile. Twins, a daughter and a son, infants when he left.
Yang and Yin—yielding to one final whim of his, his wife had let him name them. She was remarried to a Company shareholder. He doubted that she would want to see him, but he had kept in affectionate touch with the twins. Now coming of age, they were completing their engineering degrees at Kwan Tech.
He revealed his discovery to them, then to some of their friends, sons and daughters of Earthside industrialists who had been denied their Sunmarks. Working in secret, his first small group recruited physicists and engineers, designed new equipment, secured materials to build and equip two new descenders, and finally returned to Neptune on a craft cleared for Pluto.
A year and a half on the long voyage out, even on faster modern craft, they used the time to assemble the first descender. All its external equipment was robotic or remote-controlled, but its tasks would be too demanding for any computer. It was to be manned, though by only a single crew member. Both twins volunteered for the mission.
“No! Neither one!” He was dismayed. “I’ve gotten to know you too well. I love you both too much. There are others enough who want to go.”
Yang agreed that it was too hazardous for a girl. Not, however, for him. Hotly, Yin challenged that. He had always been shorter and slighter than she, the result of an old infection with one of the mutant viruses forever infesting the crowded Earth. She had led and protected him through their childhood, and she still felt fitter than he.
“We’ll toss a coin.”
Yang produced a bright new Sun dollar, let her toss it, and called heads. It fell with the new Tycoon’s golden head glinting at her.
“Sorry, Sis.” Grinning at her, he picked up the dollar. “Don’t fret for me. I beat the shaking fever, and I can beat anything I happen to meet down toward the core.”
With Chou’s protests overwhelmed, the project went forward. They installed a new skywire extension to lower the descender to a level where they might hope to pick it up again. Preparing to go, Yang seemed coldly silent, totally absorbed. But when he gripped Yin’s hand and turned to climb aboard, tears filled his eyes.
“See you, Sis,” he called though the closing hatch. “With enough diamonds to make the Tycoons cry.”
The short day was ending before the descender fell away into Neptune. She followed it down, a bright fleck dwindling into dull bluish dusk turning swiftly dark. Its strobes came on, winking like the fireflies she had known at home, slowly dimming until she lost them.
“My poor, dear brother,” she wrote that night in her journal. “Always risking everything, because he always wants to beat me. I’m sorry for him. Terrified now. And suddenly I wonder why he seemed so sure when he called the com was he somehow cheating?”
They waited for him, waited for his signal capsules, waited a year.
“A crazy dream,” her aging father told her. “We’ve followed it far enough. No hope for him now. I’m giving up.”
“I’m not.” She had been assembling the spare descender. “If he doesn’t get back, I’m going after him.”
“I can’t let you—”
“Here’s why you must.” She showed him a bright Sun dollar. “I found it last night in his room. Look at it.” She turned the coin to let him see the new Tycoon’s golden head shining through the plastic on one face and then on the other. “He cheated, and you’ve got to let me go.”
Before her craft was ready, they picked up transmissions from a signal capsule that told Yang’s story. Sinking for months as the unmanned probe had done through ammoniac rain and chemical snows, through calm and fury, he had come at last to the stagnant surface of a tar-colored sea.
“Liquid methane.” Her brother’s voice, faint and distorted, but still her brother’s crisply careful voice. “Stained, I imagine, with carbonaceous pollution. The power cells are almost gone, but I can use wind motion. Drifting now.”
He drifted for many days.
“Cliffs ahead!” In that later report, excitement lifts his voice. “Tall and lagged. Could be the floating continent of solid hydrogen the old theorists expected. Dropping ballast to climb over it. No sign of diamonds anywhere.”
