Titan

by Stephen Baxter

  She was shivering; the rain on her bare scalp was cold and actually painful. The few ammonos here had their arms tucked under their carapaces, and rain puddled on the clear coatings over their backs. And now the rain actually seemed to be getting harder, turning to sleet.

  “Shit, Rosenberg. Understanding the mechanics of the weather wouldn’t help me half so much as a hat.”

  He nodded, his motions jerky, shivering. “Let’s keep moving. At least that will keep us warm. This can’t last forever. Maybe we’ll climb above it.” He set off.

  she tucked her head into her shoulders, folded her arms across her body, and walked after Rosenberg, who was already receding into the misty haze.

  The walking didn’t require much attention, and, like her walks on Titan before, she tried to lose herself in daydreams, fantasies, to escape the dull reality of the world.

  But the dreams wouldn’t come.

  Maybe the ammonos had rebuilt her, but they didn’t seem to have put back her imagination. Or maybe there was some part of her which knew there was nothing much for her to dream about.

  By the time they reached the foot of the cliffs, the rain had stopped, but there was still a thick layer of laden cloud which obscured the upper reaches of the cliffs. The cliffs here were steep and forbidding, thrusting out of the ground like a wall, their base littered with some kind of loose scree.

  Rosenberg went forward and tried to clamber over the scree, but it was slick with half-frozen rain, and the fine plates slid over each other easily. Despite the buoyancy of low gravity, Rosenberg slipped, repeatedly, and stumbled.

  After he bloodied his nose he gave up.

  The chaotic clusters of ammonos had reduced to a couple of files here, like columns of ants. They were going head-on at the cliffs, without hesitation; their legs seemed able to clamp onto the slick ice surface, and they hauled themselves straight up even the steepest sections of the cliff. Looking up, she could see the trail of ammonos dwindling into the mist and low cloud above, their carapaces dark stains against the dull gray-red surface of the ice cliffs.

  “I wish I had their legs,” Rosenberg said, rubbing his mouth. “Come on. We’ll follow the cliffs a ways. It can’t all be as tough as this.”

  They stood, shivering, each waiting for the other to lead. Neither of them wanted to do this, she realized. The truth was, they both just wanted to go home.

  She said, “Which way? North, or south?”

  “You choose, Paula. What difference does it make?”

  “North, then.” She turned to her left and began to walk. “And if we walk all the way to the pole and find a desert there, I’ll know for sure you’re a smart ass, Rosenberg.”

  “That’s my job,” he said, wiping blood from his lip.

  After a couple of hours of steady walking over the slick ground, they came to a narrow gully. As far as Benacerraf could see it was incised all the way up the ice face, and into the clouds above. It looked as if it had been cut by a stream, which was now vanished.

  At the foot of the gully there was a short section of the treacherous scree. She stepped carefully over this, watching her feet.

  Then she came to the gully itself. Its mouth, at the base of the cliff, was broad, and there was a litter of topsoil, evidently washed down from the gully sides or from the Cronos plateau above.

  She walked forward. For a hundred yards the going was easy; the ground sloped up steadily, but the gully was broad and paved with gritty, rough topsoil. But soon the walls narrowed around her, and the base of it narrowed to a thin V. She had to walk—climb, in fact—with her feet splayed outward, braced against the gully’s two sides.

  As she climbed, the grip of her soles became less reliable, and her feet slipped from under her. The clutch of gravity was feeble, but the pain was great as she banged her knees and hips against bone-hard ice. Her bare hands soon started to turn white and numb from the cold of their contact with the ice. She pulled her sleeves down over her hands and gripped the cuffs in her clenched fists. But that wasn’t satisfactory, because the stretched material rubbed painfully at her shoulders and the back of her neck. And besides, it was almost impossible to get any grip without opening out her fists.

  Her world closed down to the aches of her body, the few feet of ice gully around her, the eroded surface in front of her face, the focused search for the next handhold. She couldn’t even move fast enough to work up a decent sweat, and she grew steadily colder. She was a billion miles from home, eons in the future, but as her discomfort closed in she might have been anywhere, she thought.

  Her irritation turned to misery.

  She climbed into a layer of billowing mist. The droplets of water vapor were hovering balls the size of her thumbnail, and they caught the diffused crimson light of the sun. They looked too big to be suspended in the air, but here they were, the swirling updraughts easily counterbalancing Titan’s feeble gravity. Walking through them was something like entering a zero-G shower. When the droplets hit her translucent suit they splashed but didn’t stick, and secondary droplets spun away, shimmering. But the drops that hit her face and hands and bald scalp spread out rapidly and soaked into her. Water started to seep inside the suit, at her neck and cuffs.

  She tried to wipe the excess liquid off her face with the edge of her hands, or her cuff. The mist as it dried was leaving a fine residue on her flesh, a sticky organic scum.

  She ached all over. The hell with this. She started to get angry.

  It she couldn’t lose herself in daydreams of past or future, then maybe she ought to concentrate on the present, the obstacles she was facing, how she could make things easier.

  Crampons, for instance.

  Maybe she could improvise something from those scrubby trees on the plain. A flexible branch, maybe a rope woven from some kind of creeper.

  She needed gloves, of course. And a hat. Maybe they could sew together some kind of fabric of leaves.

  She thought about knocking over one of those ammonos. That might solve all their raw materials problems. But if Rosenberg was right, the ammonos, inside their chill spacesuits, were breathing out ammonia and cyanogen. Slicing open one of those suits would not only kill the ammono, it would do the two of them a lot of damage too.

  Anyhow, such violence felt wrong. This wasn’t her world, after all.

  So: hats of leaves, or bark. Maybe they could stuff their suits with grass and lichen to improve insulation. They would have to do some kind of inventory of the vegetation here: investigate what they could eat, what they could use for other purposes, like construction and even medicine…

  Thinking, planning, wiping the waxy organic sheen from her face, Benacerraf continued her climb.

  At last the gully grew narrower. Looking up, Benacerraf could see she faced maybe ten or fifteen feet of sheer ice, beyond which the land flattened out. She could see tufts of grass-analogue bristling out from the lip of the plateau above her, black and wiry.

  It wouldn’t be a difficult climb, she thought. Just a little scary.

  She looked down. She’d risen almost all the way out of the mist layer now, she realized. The mist was a lumpy gray-white ocean beneath her, from which thrust this ice cliff. She could make out Rosenberg, as a toiling pink-brown speck in the mist layer, perhaps a hundred feet below her.

  She turned again, lodged her fingertips in crevices in the ice, and hauled herself upwards. The low gravity worked in her favor, and the climbing here was actually easier than the slog up the gully.

  She reached the top in a few minutes, and dragged herself up over the edge.

  The land flattened out here to form a plateau, sharp-edged by this ice cliff. Further off, she could see no sign of further uplands, although a shallow wavelike ridge in the ice hid much of the landscape from her. There was grass growing close to the cliff lip, and some of the swollen mushroomlike things. A layer of thin cirrus cloud coated the eastern sky, stained red by the light of the aged sun.

  She peeled open a couple of sea
ms to cool down. She sat at the edge of the cliff, her legs dangling over.

  Rosenberg took a further half-hour to reach her. He hauled himself clumsily up over the last lip of rock and threw himself flat against the ice, his arms outspread. His face was coated with a thin frost rime.

  “I never thought,” he said, “I’d be so pleased just to be somewhere flat.”

  She scraped the frost off his skin with her fingernails. “You’re not a physical kind of guy, are you, Rosenberg?”

  “Oh, I’m learning to be. Boy, am I learning.”

  She collected some food, mostly mushroom flesh. They drank ice-cold water from a small rivulet nearby, that fed the bigger system that had carved out the gully they’d climbed.

  When his breathing had gotten back to normal, Rosenberg pushed himself to his feet. His hands and mouth full of mushroom flesh, he did a slow scan of the world from this new vantage point. He gazed down over the gray, lumpy clouds that covered the lowlands, then turned and looked inland.

  He stopped. Even his jaw ceased its chomping.

  “Rosenberg? Are you okay?”

  He was staring inland, a green light reflecting from his face. “Stand up,” he said. “Stand up and look at this. My God.”

  She got to her feet, her legs still aching, and stood alongside him.

  The sky to the east, over the interior of this ice continent, had cleared; the cloud layer was breaking up. The sun was a huge blood-red ball, battered and pocked, dominating the orange sky above.

  There was a layer of green light at the horizon.

  At first she thought it was a smog belt. But it was flat and sharply distinguished, at its upper edge.

  It was a roof.

  There were tall trees—no, towers—evenly spaced within the green. And the towers were tall, she realized now; they were poking above the horizon, their bases hidden by the curve of the moon.

  Some huge form, diamond-shaped, moved between the towers, within the roofed enclosure.

  “My God,” said Rosenberg. “I was starting to think I dreamt it. That’s where I was, the first time.”

  The first time? “Where?”

  “In there. That’s a worldhouse. The last refuge of the old ammonia-based life system. It’s like a greenhouse. Except, colder within than without. In there, the conditions must be as they were when the ammono life was at its peak, when it covered Titan. That’s where they retreated when the sun got too hot, when the ammonia oceans started to boil and the bedrock melted. It must be where these ammono beetles are coming from now.”

  “It’s like our CELSS farm.”

  “On a gigantic scale… Oh.”

  The mist in the air was lifting. And in the east—beyond a horizon obscured by that immense artifact—Saturn was rising.

  Saturn was autumn brown, against the green sky. Perhaps a quarter hemisphere showed. Time seemed to have been kind to the huge planet: Benacerraf could make out the familiar bands of cloud, tipped up almost vertically towards the ruined sun, and the splashes of white that marked interior-driven storms…

  “The rings,” she said. “Rosenberg, what the hell happened to the rings?”

  The planet’s huge face looked denuded, without that narrow, tilted-up ellipse of banded light, the matching, complex shadows in the cloud tops.

  Rosenberg said, “They were only chunks of ice, Paula. I guess it just got too hot.” He threw down what was left of his mushroom and dusted off his hands. “Let’s go see what’s over the next ridge.”

  He stalked off, eastward. He bounded away, taking big bunny-hops, and was soon fifty yards ahead of her.

  His mood had swung to its manic, energetic pole, she thought gloomily.

  She followed more sedately, trying not to pine for Saturn’s rings.

  The ridge, maybe fifty feet tall, was a pressure wave frozen in the ice, and easy to climb. Rosenberg waited at its crest for her.

  From the crest, the landscape seemed to open up, as the horizon receded to the east. The land beyond the ridge was pretty flat, though in places cracked and compressed.

  At the foot of the ridge there were beetle ammonos, the first she had seen since leaving the plain. They toiled in complex patterns across the barren ice fields here. They made their way in roughly radial patterns to what looked like a jumble of low hillocks at the center of the plateau, neatly sliding over or around the worst crevasses. That cluster of hills was perhaps five miles from them and a half-mile across, or less. The hills thrust irregularly out of the plain, their contours rounded, as if melted, their facets glimmering in the light of Sol and Saturn.

  Glimmering.

  Actually, it looked like a downtown.

  “Oh, my,” Rosenberg was saying. “Oh, my.”

  “That’s artificial,” she breathed. “Isn’t it, Rosenberg? Holy shit. Those aren’t hillocks. They’re buildings. That’s a city.”

  “Oh, my.”

  They both moved at once, as if some spell had broken. They hurried forward, hopping carelessly down the side of the ridge. Rosenberg led the way, and the pace he set was more a half-run than a fast walk. The ice here was flat and not too badly broken up, and it made for fast progress. Even so, Rosenberg tripped a couple of times.

  A part of Benacerraf would have liked to take this a little slower. One bad fall, one twisted ankle—or, worse, a break—could be a catastrophe for both of them.

  Part of her felt like that.

  The greater part of her soul was with Rosenberg in his desperation, running ahead of the constraints of the ice, running ahead of caution, to the city on the plain.

  They ran more frequently into files and clusters of ammonos, as they picked their way earnestly across the ice. Benacerraf, with her residual caution, tried to avoid the ammonos. Not Rosenberg, though: his head was up, and he simply ploughed through the ammonos’ orderly ranks. But they reacted smoothly to him, their files breaking and reforming as he stomped through. It was like, she thought, seeing a column of gigantic ants skirting a boot placed in their path.

  Even Rosenberg slowed, though, as they reached the edge of the city.

  It was, she thought again, like walking into a downtown.

  The structures here were grotesque spires of ice: some, she guessed, were more than a half-mile tall. The nearest was an octagonal pillar, tipped away from her, Pisa-like. The ground around its base was littered with irregular blocks of ice, some feet high. The surface beneath was smooth ice, as flat as a freeway. And slick, with a thin layer of surface water. Like an ice rink.

  Machined.

  She clambered past the worst of the ice blocks and walked forward, across a free stretch of floor, until she reached the wall of the structure. She looked up at it. The wall, one of the eight comprising this octagonal cylinder, narrowed as she peered up, merging at infinity with its neighbors into a crimson-gray line.

  Suddenly, staring up at the pillar, she felt giddy, as if with reversed vertigo; some primitive primate fear, as Rosenberg would say, that the thing might tumble down and crush her seemed to be about to overwhelm her.

  She put out her hand. She touched a cold, hard surface.

  The ice was like rock, but there was a slickness to it. When she pulled away her palm, her skin was wet. And now she looked more closely she could see the edges of the building, between the huge facets, were smoothed over.

  The building was melting.

  She heard Rosenberg’s footsteps receding, so she hurried around the octagonal pillar and followed him, proceeding deeper into the city.

  It was like walking through an ice-sculpture caricature of Manhattan. The buildings—spires and pillars, even some narrow, inverted cones—towered over her, their washed-out crimson-gray lines obscuring the sky. In some places she could see lacy bridges connecting the peaks of the structures, but there were a lot more stumps and broken arches than complete spans. The narrow, regular streets between the buildings were cluttered up with rubble, smashed-up ice fragments, some of them huge.

  About all of
this there was a sense of smoothing out: of rounded corners and edges, of melting. There were even icicles dangling down from the stumps of bridges. Most of the buildings seemed open, with immense archlike doorways like cathedral entrances. When she peered inside she found nothing but scattered rubble.

  The ammono beetles toiled in thin files towards and away from the dense center of the city. With what seemed an inexhaustible patience they worked their way around the innumerable ice-fall obstacles that cluttered up the orderly streets; if she watched for a while, Benacerraf observed that the ammonos always followed the same path around each obstacle, like ants following a biochemical trail.

  She met Rosenberg at the center of a small square, bounded on all sides by elephantine ice walls. He was peering up at the huge buildings. There was water on his cheeks; it shone in the pink-gray light of the ice walls.

  “All the damage is at ground level. See? That’s where the walls are smashed up and cracked…”

  She looked at the building with new eyes. “You’re right, Rosenberg. So how did they get this way?”

  “Isn’t it obvious? They fell, Paula.” His eyes were a red-rimmed mess, she noticed. Evidently his mood had crashed again. “Suppose you were building, here on Titan, in this one-seventh gravity and all this thick air… Wouldn’t you build up as high as your materials could go, huge Gothic structures, stilts and spires and bridges miles high? Why, you could pump your walls full of air and use buoyancy to get even more of a lift… But then the sun blew up, and the damn stuff just started melting.”

  She walked up to him and took his hand. “Shit, Rosenberg. You’re crying again.”

  He looked down at her. “Don’t you get it? Look around you: the ancient, ruined crystal city… This is Xi City. Maybe the houses turn to follow the sun—”

  “What?”

  “Didn’t you read Bradbury? This is the way the Solar System was supposed to be, Paula. This is why we went to the Moon, why we sent out the probes to Mars.” He walked a few paces ahead, and turned around, his arms outstretched to the huge, sculpted ice walls. “This was what we were looking for all the time. This! It’s just come billions of years too late, is all. Damn, damn…” He ran a hand over his face, smearing tears and snot. “I’m sorry.”