by Greg Egan
“I still think my plan would have left us more at ease,” Judith declared wistfully. “We would have been in control all the way.” She’d wanted to position the ropes in advance, by lowering a heavy object to anchor them, and then have the basket ride down the central rope, with the passengers able to start and stop at will. Seth could see the attraction of this kind of autonomy, but the engineers had judged her gadget for governing the speed of descent to be too complicated. And if a stripped ratchet in a distant winch could cause problems, any damage to its counterpart in the basket itself would have been much harder to deal with.
“Surely you’re accustomed to someone else dictating your movements?” Andrei protested. It was the kind of joke that any of the Baharabadi might have made among themselves, but Seth could see Sarah tense with displeasure, as if it were some kind of personal attack against her and her Sider.
“I just want to be down there as soon as possible,” Raina interjected. “With rock beneath my feet instead of thin air.”
A pair of messengers from the rope teams arrived. The Walker pulled the inspection reports out of a protective bag and handed them to Raina; she looked them over then announced, “Time to go.”
The expedition filed out into the rain. Seth followed the path to the middle platform, then gripped the guide rail tightly as he sidled toward the far end where the basket was waiting below. Mercifully, there was a small roof here to keep the rain out, and a couple of carefully placed lamps. Raina supervised the boarding, checking each Walker’s safety harness before letting them climb down into the basket.
«Don’t look down,» Theo begged him as Seth’s turn came to approach the rope ladder.
«You keep forgetting that you’re not here.» Seth let Raina help him with the harness, then he reached across the hole in the platform, gripped the ladder, and stepped onto the nearest rung.
Enough light from the lamps was spilling through the hole to show the roof of the basket gently swaying against the darkness as Seth began his descent. Despite its sheltered location, the ladder had grown slick from wind-blown rain, but he wrapped each hand tightly around its rung before releasing the other, and willed himself not to think of the fear and shame that would come if he lost his grip and ended up swinging in the harness.
As he approached the basket’s roof he suffered a moment of vertigo, unable to shake the absurd notion that he might accidentally step onto it and go skidding down into the blackness, rather than passing through the hatch into the safety of the interior. But then he caught sight of Sarah standing near the base of the ladder, her upraised face lit by the basket’s own lamp; with his eyes locked on hers, he ignored everything else. When his feet touched the floor of the basket he found that it was not quite steady, but Sarah helped him out of the harness then jerked the rope and called up, “He’s safe!”
Ada followed, then Raina and Amina. A member of the rope team pulled up the ladder and harness, then Raina slammed the hatch closed. “No one’s changed their mind?” she asked cheerfully; Seth wasn’t sure if she was serious, but she received no replies.
The basket was about the same size as the balloon’s, but with five Walkers and the expedition’s supplies it was much more crowded. Three windows looked out into the rain, with the lamplight doing as good a job as Theo’s pings to reveal the downpour, while to the sheltered north Theo showed the platform’s supporting girders all the way to the cliff face.
“Time to get seated,” Sarah suggested. She joined Seth on one narrow bench, while the three west-facers sat opposite. Seth pictured the rope teams signaling each other with lamps, preparing to begin the unreeling together. The changing geometry of the ropes ought to be enough to alert them if they fell out of step, but there would be no cues to compare with the sight of a balloon the size of a building rising up into the sky.
“It’s started,” Theo said. With the basket swaying in the wind Seth hadn’t felt its downward motion commence, but the girders were already rising out of sight to the north, leaving nothing but the bare cliff face in view. The lamp suspended from the ceiling began oscillating with a new, steady rhythm that stood out against the vagaries of the wind: the rhythm of the rope teams, smooth and practiced, promising to bring the travelers safely to their destination.
The cliff face disappeared behind an ever-thickening curtain of rain, as the same geometrical constraints that had sent the rising balloon to the south played out for the descending basket. Seth exchanged a glance of shared relief with Raina: it would take much more than a freakish gust of wind now to see them hit the rock.
Ada took something from her pocket and held it up to her Sider’s left pinger.
“What’s that?” Seth asked.
“A barometer,” she replied. “It weighs the air above us; it ought to show an increase in pressure as we descend.”
Seth had never heard of such a thing. “Where’s it from?”
“I made it myself.”
“From whose plans?”
“My own.”
If that was true, then her ingenuity was impressive—but it rendered one aspect of the design disturbing. The dial of the thing, which presumably displayed the quantity it measured, was a north-facing circle, so she’d never be able to see it for herself. Somehow, Seth realized, the silence of her Sider had lulled him into thinking of her as side-blind: alone but independent, making her way in the world with nothing but her own senses. And that wasn’t remotely true. On the contrary, she clearly took the assistance of her stupefied slave for granted.
She must have seen the unease on his face, because she put the device away. Seth had no wish to blame her for his own confusion; he composed himself and lowered his gaze.
Theo said, «How can you weigh the air?»
«I’m not the one you should be asking.»
«It sounds like a hoax to me,» Theo grumbled. «It probably tells fortunes and makes matches as well.»
«I really wouldn’t know.»
The sound of the rain on the roof stopped abruptly, though when Seth looked north through Theo’s view he saw that it was still falling in the distance. Once the edge of the rainstorm was too far away to ping, the windows showed nothing in any direction, and all he could hear was the rhythmic creaking of the roof as the tension in the ropes rose and fell.
Andrei smiled uneasily. “I’m used to leaving the crowds behind, but not the world itself.”
Sarah said, “Even Theo thinks we’d need to go farther south to achieve that.”
In the silence that followed, Seth pictured her words spreading out into the darkness and vanishing, swallowed by the emptiness around them.
at first, what theo was showing him through the northern window looked like distant rain or fog. Seth waited for the thin presence to dissipate, or simply recede as the basket continued to the south, but instead, very slowly, it drew closer.
“That’s rock?” he asked. “That’s the slope?”
“It must be,” Theo replied. “It doesn’t match the practice ramp, but I never expected the texture to be the same.”
Seth hadn’t been expecting much ping-back, given the geometry, but instead of the faint, smooth sheen that their mock-up had exhibited, the real thing registered as a thousand tiny flecks that required a positive act of the will to perceive as belonging to a single surface at all.
The ramp they’d used as a surrogate for the slope had been made by taking slabs of rock and propping them up at extreme angles—a tricky business, but a great deal easier than carving a similar structure out of the side of a mountain. The catch was, tilting an initially horizontal surface to such a degree stretched out all of the rock’s corrugations and crannies to the point where they became imperceptibly shallow—whereas it was apparent now that the slope itself had achieved the same overall gradient by a process in which there had been no tilting to smooth away its ordinary blemishes.
Amina said, “We’ll learn to make sense of this too, it’s just a matter of time.”
As the sl
ope came nearer, its foggy appearance sharpened dramatically in places. These streaks of clarity seemed to arise from small cliffs where the incline had collapsed, leaving near-vertical rock faces above rubble-strewn terraces, as if from an abandoned project to build roads across the impossible landscape, or tame it for agriculture.
The basket skimmed the terrain ever more closely, but though proximity revealed more details in the rock the speed of the descent left Seth with no time to study them. They were traveling almost parallel to the slope now, but he felt himself growing tense at the possibility of a premature impact. For all the balloon surveys and all the winch tests, the system could not be so finely calibrated nor the landscape so perfectly mapped as to promise that the basket would be motionless at the instant it met rock.
They slowed, and began to drop. Seth wished belatedly that he’d asked for an observation port in the bottom of the basket: even without sunlight, they could have lit the ground themselves for the final approach, and even without Judith’s vision of total autonomy they might have devised some way to steer clear of the most dangerous obstacles.
The basket thudded to a halt. For a second or two there was stillness and silence. Then the floor creaked and tilted, and they began to slide upslope, accompanied by a horrifying grinding sound. Seth clung to his seat, glancing up to see the others bracing themselves awkwardly, grim-faced with the effort. As they built up speed, the lamp canted so far to the south that it came halfway to the floor.
The ropes snapped taut. The roof moaned and shuddered and the lamp swung back and forth, dividing the cabin with a hallucinatory hyperbola. Seth waited anxiously to see if they’d reached a stable resting point, with the forces from the ropes and the ground not merely in balance for the moment, but actively disposed to resist any further motion.
The lamp’s oscillations died down. Raina rose and began lowering one of the supporting legs that were tucked inside along the southern wall of the basket; Seth was about to do the same, but Sarah was on her feet before him.
When the legs were locked in place, Andrei began testing the stability of the setup, at first just swaying on the spot, then cautiously sidling back and forth to gauge the basket’s response. Seth joined in; he could hear the floor creaking, but as far as he could tell it didn’t shift. The small portion of the slope in Theo’s view through the northern window was confusing: an indistinct slab of conflicting cues with unstable meaning, like a Sider’s idea of an optical illusion. But as he moved around the cabin and observed the way the texture responded to his changing position, it began to seem less strange.
While they waited for the twilight that would have to suffice in lieu of a true dawn, they took their packs out of the storage hold and divided up the provisions. Not knowing what the local vegetation would be like, they’d come laden with nuts, seeds and dried fruit. Seth wondered where Ada had placed her stash of the stupefying drug; there were no puffballs mixed in with the more conventional supplies, but perhaps the concentrated form was potent enough that she could carry a hundred days’ supply discreetly in her pocket.
Raina opened the hatch in the roof and unrolled the rope ladder beside it. She lit a second lamp and ascended. After a minute or so, she called down, “There’s room for two at a time up here, if anyone wants to join me.”
For a moment, mutual deference paralyzed her colleagues, but Seth was standing closest to the ladder so he stopped wasting everyone’s time. As his head rose above the hatch, he paused to let his eyes adjust.
The light from Raina’s lamp could not reach far, but the brightest part, near the shadow of the cone guard, struck the slope half a dozen paces from the spot where the basket had come to rest. The brown rock looked abraded, but hard enough to have survived for eons, like some outcrops Seth had seen in the desert. It was unlikely to crumble under their weight; the question would be whether they could keep their balance on it, when all their experience had come from an imperfect approximation.
“Look west-south-west,” Raina suggested.
Seth climbed all the way through the hatch and stood on the roof to get a better vantage. To the south, Theo was utterly blind; if the slope wasn’t exactly forty-five degrees, it was near enough to ensure that any pings in that direction met nothing but air. Seth tipped his head back to the west and peered out across the illuminated ground. After a moment he noticed a line cutting across the edge of the lamplit terrain that had nothing to do with the geometry of the beam.
“Do you think that’s a drop?” he asked.
“Yes,” Raina replied. “But it’s not too deep.”
“How can you tell?”
“You can’t see the bottom clearly, but you can see that the lamp’s reaching it.”
She was right: the bright edge of the beam on the contiguous part of the slope vanished abruptly, but it was possible to discern a faint, shifted band of light where it struck another surface below.
Theo said, “We might have got lucky.”
Seth climbed back down into the basket to give someone else a chance to take a look. As he descended, Ada was standing nearest to him; he couldn’t quite bring himself to offer her a verbal invitation, but he gestured toward the ladder and she did not demur.
The mood of the other travelers was already optimistic; they must have pieced together the implications of the rooftop conversation. But Judith wasn’t satisfied with mere luck. “I could have put us down with a terrace right on our doorstep,” she boasted.
“Next time,” Nicholas suggested.
“Why would there be another expedition?” Judith asked irritably. “Whether this thing is small enough for the migration to detour around it, or not, sending in another team isn’t going to change the answer.”
Nicholas said, “Maybe. But I think people will still want to know exactly what this place is, and I doubt it’s going to be small enough for us to answer that in the time we’ll have.”
Theo was amused. “If the edge runs geologically west and continues unbroken, we could follow it for as many generations as have already lived, and still not return to where we started.”
when a pale light began to spread across the sky from the north-east, Seth watched with a sense of gratitude that he would not be facing the fierce dawn that had come to the land above the cliffs. The twilight did nothing to dispel his hopes about the terrace, though the exact scale of the drop remained hard to judge from a distance.
Andrei and Nicholas volunteered to be the first to test the terrain. Sarah helped Andrei into a harness then Seth joined her beside the spools of safety rope, while Raina and Amina, and Ada, watched from the roof.
Andrei slid open the western hatch. The northern edge of the basket’s floor was resting against the rock not far from the doorway, but the slope still made for an awkward disembarkation. After binding a small wedge to his right foot, Andrei lowered a single stilt to the ground and placed his left foot on the stilt’s platform. They’d all gained some proficiency in the strange technique, but the practice ramp had been an imperfect substitute, so Seth watched anxiously as Andrei shifted his weight onto the stilt, checking that it wouldn’t go skittering north, then placed his wedged right foot on the ground and stood.
Gripping the stilt by its handle, he raised it and pivoted forward on his right foot, then brought it down. Seth resisted the urge to offer advice: Andrei surely knew that in his eagerness to make progress he had placed the stilt too far downslope for safety. A moment later he half-reversed the step. Then he brought his right foot forward and began repeating the whole cycle, breaking into a halting walk as precarious and comical as their attempts on the ramp, but no less successful.
Seth and Sarah played out the ropes as Andrei shambled westward. Once he’d found his rhythm he became more ambitious and began to veer a little to the south, bringing him closer to the drop. Navigating the approach would not be easy: nothing due south would be visible to Nicholas, and at best a small patch would lie in Andrei’s peripheral vision when he looked down. All he co
uld do was fix a point on the edge in his mind while it was still in front of him, and then hold on to his memory of its relationships with the rest of the terrain when it vanished into his dark cone.
Theo said, “I bet we’ll find no animals here. Even if there’s a gentle way down the cliffs that we’ve yet to discover, there’s nothing to the north that could have prepared them to move safely on a gradient like this.”
“There might be plants, though,” Sarah replied. “Of all the seeds and spores blown around on the wind, some hardy species might have lodged in a few crevices.” To Seth all the rock in sight appeared barren, but he didn’t want to dismiss the possibility.
“This is perfect!” Andrei shouted excitedly. He’d come to a halt a pace north of the drop. “We’ll be able to reach the bottom easily. The ground still slopes a little to the south down there, but not so much that we’ll need stilts.”
“How far does it continue?” Judith called back.
“As far as I can see.”
Raina was silent, but Seth could not imagine any reason why they should refuse this gift. The terrace might not run as far west as they needed to go, but wherever it ended it was hard to see how that could leave them in a worse position than if they’d chosen to limp across the slope from the start.
“I’d better take a look,” Raina decided.
When Andrei and Nicholas returned, they took Seth and Theo’s place at the safety rope while Raina and Amina repeated the short journey. Seth stood back from the doorway, unable to get a clear view but reluctant to join Ada on the roof. He’d thought he’d reconciled himself to the need to treat her with civility, but now the whole idea of being at ease in her presence felt shameful.
Raina reported what appeared to be a number of boulders scattered further down the terrace. If they really were loose objects that had come to rest there—rather than outcrops of some tougher underlying rock that had resisted the collapse—then it seemed unlikely that the weight of a few people could trigger a fresh subsidence. But she could only be sure of that if she went down onto the terrace and examined the boulders directly.
