by Greg Egan
They sat down at the table and began to eat.
“How quickly do you think the new villages will be established?” Marion asked. When Rosalind hesitated, she made the question more specific. “Do you think you’ll be seeing Celine there?”
“I hope so.” The older women had no expectation of reaching Tvíburi themselves. Rosalind turned to Celine. “If you ever have time, there’s no harm in practicing with a glider. If you start from low jumps, it’s not dangerous.”
“Practice, and wait for the signal,” Marion said.
Rosalind nodded. “By the time our children are old enough to help us in the fields, we should have sowed enough land for the farms to be visible through any decent telescope. Though I’ll be happier still if I’m the one who looks up, to see a new geyser sprouting from the limb of Tvíbura. In which case, migrants will still be welcome…but we won’t expect quite the same influx.”
Celine laughed, but Rosalind’s mother looked horrified. Rosalind offered her a questioning frown. Would it be better if I wished an endless famine upon the world, just to make myself less lonely?
Her mother said fervently, “Tvíburi is the future. We all know that. You’re giving us a future we’d never have otherwise.”
Rosalind was embarrassed. “I’ll do my best,” she said.
Mercifully, Celine was impervious to her aunt’s solemnity. “How many stairs are there in the tower?” she asked. “From bottom to top?”
“I don’t honestly know,” Rosalind admitted. “If I tried to calculate the total now off the top of my head, I’d probably get it wrong.”
“Don’t worry,” Celine replied. “When it’s my turn, I’ll make sure to count them, and I’ll tell you next time we meet.”
The last level of the tower was the tallest, and it had no stairs at all. Rope ladders stretched between the annular rest platforms, but though the bottoms of the platforms were helpfully painted red and the top surfaces blue, Rosalind struggled to perceive any fixed direction as up or down. She felt like an insect crawling along inside a hollowed-out tree branch, which a child had picked up and was whimsically turning this way and that. It was not that she feared being dislodged, and it seemed absurd to imagine that she could ever lose her way. But as she moved, hand over hand, in near weightlessness through the tube of luminous ice, the sense of disorientation was impossible to shake off. All she could do was embrace it, and hope she wouldn’t throw up.
“Matilda told me it was beautiful up here, but I never imagined!” Joanna called out, from a dozen rungs behind her. Matilda had worked on completing the tower, when the only thing at the open end between the ice-farmers and the void had been a series of tarpaulins, which were meant to trap the air but were forever coming loose or getting torn. She’d once told Rosalind that she’d often had to spend half a day without breathing, while the tarps were repaired and air was pumped in from the level below.
Sigrid said, “I’ll reserve the word beautiful for the first sight of fertile soil between my fingers.” She glanced across at Rosalind from her adjacent ladder. “Or better yet, my first child born on that soil.”
“Yeah, yeah,” Joanna replied tetchily. “It’s all about the practicalities; the rest is just a distraction.”
“Do you think a thousand people should have died just to give you a pretty ice sculpture?” Sigrid retorted.
“No. But that doesn’t stop me appreciating every part of what they built.”
Rosalind knew better than to urge them to make peace, or even just spare her from having to listen to their nonsense. They’d never actually come to blows over these meaningless quibbles, so if they found the bickering helped them pass the time, who was she to object?
As their last day attached to their birth world wore on, the sun crept below them without actually setting, even as Tvíburi turned gibbous behind the wall of ice. Rosalind couldn’t really discern its shape, but the slowly growing illumination from the west side of the ice ahead of her was all she needed in order to picture the new dawn sweeping over the face of the twin.
For all that the rules of light and geometry rendered everything she was seeing explicable, it remained deeply unsettling. If anything, what shocked her was that these strange sights made so much sense. As a child, she’d experimented with lamps and fruit, visualizing every stage of this journey. For the real sun, and the real worlds, to recapitulate her clumsy shadow play made her feel like someone half prophet, half puppet, unable to decide if she’d shaped this future, or if it had reached back in time and shaped her.
Then again, maybe light was just light, and spheres were just spheres, and the humblest piece of fruit cast its shadow no differently than the world itself.
When the sun finally went behind Tvíbura, leaving the softer glow of their destination to light the way, Rosalind counted the number of annular platforms she could make out above her—and for the first time, it had fallen from the usual eight all the way down to six. At first, she thought she might be losing a couple to the change in the light, but as she passed the nearest of the six, nothing emerged in the distance to make up for it.
“Almost there, almost there, almost there!” Joanna chanted excitedly.
“Do you think we’re blind?” Sigrid replied irritably.
“No, I think you’re entirely insensate.”
Rosalind was beginning to suspect that the only thing that would keep them all from driving each other insane would be the prospect of making the farms big enough to start luring fresh blood from Tvíbura. The six expeditions would amount to forty-eight people in total, but they might not have much time to visit each other’s villages. Only new migrants would swell the numbers in each one, and bring some semblance of normalcy.
As they approached the end of the ascent, even Joanna fell silent. Rosalind saw the five women who’d climbed ahead of her leave their ladders and enter the departure hut. And then she was in there beside them, clinging to a hand rail, watching Sigrid clamber over the edge of the entrance, then Joanna too. She looked around and everyone was there: Anya, Kate, Hildur, Sophie and Frida. She’d wanted someone to be missing, just so they’d have an excuse to climb back down and investigate the absence. But apparently everyone else had been relying on her to be the one who ducked aside and hid on a platform. Joanna should have done it; she was the last, the only one of them with a chance to act unseen.
“Are you all right?” Kate asked.
“Just a bit dizzy,” Rosalind replied.
“Take a long, deep breath,” Kate suggested.
Tower workers had been up here before them, carrying the supplies and preparing them for the drops, but since even the weather on Tvíburi might influence where each glider landed, it had been decided to dispatch both people and provisions as close together in time as possible. When her gaze fell on the exit, Rosalind felt naked without her glider at hand, but if everyone had done their job it would be waiting for her outside, already assembled.
People joked and embraced each other awkwardly in the weightlessness, exchanging their last words before Tvíburi. Anya went through the exit first; there was something comical about watching her carefully sealing in the air behind her, as if that mattered to any of them now. But it would only be a few days before the second expedition began their own ascent, so it would hardly be polite to deplete the pressure in the entire top level ahead of their arrival.
As the others followed Anya, Rosalind hung back. She’d spent most of her life preparing for this moment, and she believed that she and her friends had done everything possible to understand and lessen the risks. But if every jump she’d ever made might have killed her, none of them had induced the kind of dread she felt now. It clamped her hand around the rail beside her so tightly that she feared her injured finger would break again, while every other muscle in her body turned to mush. All this, even with her brothers comatose. You have no idea how lucky you are, she told them. If only she could have slept through the whole journey herself.
Sigrid
entered the chamber; only Rosalind and Joanna remained in the hut.
“You first,” Joanna insisted.
“Why?” There was usually no one more impatient.
“I don’t know,” Joanna admitted. “I just like the idea of being alone here for a while. Saying goodbye to the tower on my own.”
“If you don’t come through, you know we’ll come and grab you,” Rosalind joked.
“Only if you can catch me. If I jump down the center of the tower—”
“If you jump down the center of the tower, you’ll fall so slowly that anyone crawling on the ladder could overtake you in no time. In fact, the ice-farmers probably miscalculated: I bet we’re past the midpoint, and you’d actually fall upward.”
Joanna smiled, and gestured at the exit. “Sigrid must be through by now.”
Rosalind pulled herself over to the door, got it open and dragged herself into the chamber. Contorting in the darkness to check each seal, she lost all sense of the direction in which her legs had originally been pointing, until she realized she could recover it by thinking about the doors’ hinges. When she finally emerged onto the balcony, she was the right way up—at least in Tvíburan terms.
She raised her eyes toward Tvíburi. She had never seen it clearly, unobstructed, from any other point on the tower, so all she had to judge this apparition against was the view from the ground. But if the swollen disk was duly magnified, it still did not look close enough to be welcoming. It was not at all like staring down at the ground, not even from her highest jump. It was just a circle of light in the void, and nothing in her instincts promised her that she wouldn’t simply veer off course and vanish into the endless blackness around it.
Joanna touched her shoulder. Rosalind turned and leaned toward her, then pressed her forehead against her friend’s. I can do this, she insisted to herself. What was the alternative? Crawling back down to the ground, mocking all the dead workers and starving farmers who’d given her the chance for a new life? Curling up in the void and drifting away to die?
Anya and Hildur had already started dispatching the supply gliders. Rosalind watched as the two of them maneuvered the next one onto the catapult. At some point, Joanna had argued that the members of the expedition would easily be strong enough to send themselves, and all the cargo they needed, plummeting into Tvíburi’s embrace by muscle power alone—and no doubt that was true, but the consensus had been that a more consistent force was needed if they were to have any hope of arriving within a day’s walk of each other, let alone the supplies.
The eight passenger gliders were tied to a rail at the far end of the balcony, and some of the other travelers were already making their inspections. Rosalind dragged herself over and joined them. She had no trouble identifying her glider; the style and materials were exactly the same as the one that had ended up in pieces on the ice field. She checked every rod and every seam, but whoever had put it together for her had done a good job. Matilda, probably. Rosalind would miss her, though hopefully not for long; Matilda had sworn she’d make the crossing herself at the first sign of greenery on Tvíburi.
Anya wound the catapult again, then she and Hildur fetched the last of the supply gliders. Each of the twelve crates being dropped contained a mixture of items, so that even if only one was recovered there would be no essential tools or provisions that were entirely absent. Rosalind did not believe for a moment that all twelve could be lost, unless they’d miscalculated some detail of the flight so badly that none of the more delicate, flesh-and-blood cargo would survive the journey either. But she still found herself hunting for a reason for her sense of apprehension. The air might be poisonous, the soil might be barren, the wildlife might be fierce and predatory…but those risks had been obvious from the first day Freya herself had suggested raising the tower. Rosalind was only afraid of the dangers no one had thought of before—and her chances of outguessing all her colleagues and predecessors at the last moment seemed slim. She had to reconcile herself to that, just as she’d accepted all the known risks. Just as she’d pictured her body a thousand times, torn apart as it skidded across the ice, she had to picture the eight of them, alive and healthy, gathered in their new village, wailing and screaming at each other that they’d been fools beyond measure for failing to prepare for, failing to bring, failing to imagine…the thing that she could not conceive of.
She closed her eyes. There, it’s done.
She opened them just in time to see the last supply glider slide along the catapult and disappear into the void.
Rosalind grabbed hold of her glider and started dragging it toward the machine. There was no order of departure that they’d all agreed on in advance, but as the flier who’d tested every new altitude from the tower, she did not believe anyone would contest her right to go first, one more time. And she could not hang back, she could not go last. She was strong enough to be the first to die, if that was the fate they were all about to share, but the idea of standing on the balcony alone filled her with an unbearable sense of desolation. Let Joanna take that role, if it was what she wanted.
After Anya finished winding the catapult she helped position the glider, then she and Hildur held it still as Rosalind climbed in beside it and strapped herself in place. They had all rehearsed the procedure a dozen times, almost weightless, in a closed room three levels below. The only difference was that this time there would be no cushioned barrier to bring her to a gentle halt.
With the glider and the catapult blocking her view, Rosalind pictured the scene on the balcony, and judged the time. Too soon, and the act would seem abrupt and alarming, too late and people would start to worry that she’d lost her nerve.
But when the perfect moment came, she didn’t hesitate, she just kicked the release lever. The catapult’s response was too fast for her to analyze; she looked down past her feet and saw the tower below her, a needle of glinting ice that seemed to narrow down to nothing long before it touched the ground—and then even the top of it retreated into invisibility, leaving her with the gray disk of Tvíbura, and beyond its edge nothing but stars.
Above her, the nose of the glider limited her view, but she could see the world’s shadow just beginning to encroach on Tvíburi’s brightness. The progress of the eclipse would give her a sharper sense of time than the slower motion of the arcs of dawn and dusk; the shadow would come and go in slightly less than one seventh of a day, while her journey was predicted to take about one fifth. Until she hit the atmosphere, she would be part of the same majestic gravitational machinery as the twin worlds themselves, and unless the catapult had been egregiously misaligned or mis-calibrated, there would be no real uncertainty in her trajectory until the very end.
She was surprised at how calm she felt now. Once the tower had vanished, she’d had no cues to provide any sense of motion, and it would take a while yet for the tug of Tvíburi to add much to the catapult’s initial impetus. She glanced back down, hopeful for a moment that she might catch a glimpse of whoever had followed her, though she knew that was absurd. If they’d wanted to cheer each other with their presence along the way, they should have contrived some kind of massive, blazing lamp that could burn in the void, turning each traveler into a beacon for the rest.
In the void, the stars were only a little brighter than on the ground, but they were impossibly sharp, and their colors far clearer. Rosalind found it strange that they were all so much bluer than the sun, when they were thought to be suns themselves, perhaps with worlds of their own. But who would ever know that for sure? No telescope could reveal it, and no traveler could endure the journey it would take to find the truth firsthand.
Her mind turned to her mother, but behind the ache of separation she could still find reasons to be content. No one would let her mother starve, and even if a majority of the young people began to leave Tvíbura, having fewer mouths to feed would help make up for the dwindling harvests. The village councils had had generations to plan for the transition, and her mother still had many f
riends who would be staying behind with her. Tvíbura would not become a wasteland or a graveyard—not in her lifetime, maybe never at all. Let her see her daughter’s farm from afar before she died; that was all that Rosalind could hope to provide for her, but it would be no small thing.
By the time Tvíburi emerged from its twin’s shadow into full daylight, proximity had changed everything. Rosalind had lain beneath the telescope, night after night, sketching maps of this terrain—committing as many features as she could to memory, preparing for the time when she’d lose the luxury of an all-encompassing view. But even those meticulous acts of cartography had never quite made the land real to her, and to see it now with her naked eyes in more detail than the telescope had ever revealed made her feel as if a story that she’d cherished and learned by heart, but never taken to be more than an entertaining myth, was suddenly bursting out from the pages of a book and wrapping itself around her.
The gray mountains were taller, and far more numerous than those of Tvíbura, which suggested that the geysers had always been more active, piling up insanely high deposits of soil fast enough to outpace erosion and allow their own weight, and the passage of time, to solidify them into rock. But even the flatlands rose up from the ice, high enough to prove that they were being constantly replenished. People had argued that if the soil here was the same as Tvíbura’s, then the seeds that must surely have taken a ride on a geyser now and then would have left the twin world covered in grasslands, but Rosalind was not convinced. Even over the eons, the number of chances for a seed to have made the journey and land, undamaged, on anything but ice need not have been so great as to prove that the soil itself was inhospitable.
The storybook world expanded below her, with geysers and mountains retreating into the distance as the ice field commandeered the plot, preparing a thousand-page monologue detailing its every ridge and crack. Rosalind felt a prickling sensation on her skin. The glider itself was steady, but she could feel the panels growing warm around her back.
