Dichronauts

by Greg Egan

  Iqbal wasn’t finished; he returned with a solid square of timber, which he slid carefully under the existing base—with Theo squirming up to raise his lower pinger off the blanket—and then secured with eight pegs. Now it would be possible to lift the whole thing without any danger of Theo sliding out.

  Lana had joined the crowd beside the enclosure, and Dahlia translated a question from her. “She wants to know if this is an ordinary part of our . . .?”

  “Life cycle,” Seth suggested. “Tell her it’s not very common. Some of us never do it.”

  “Some?” Ada interjected.

  Seth listened to Dahlia’s exchange with Lana, reconciled to the fact that he’d never learn to extract any meaning from the noises themselves, but still hopeful that he could glean some small insight from the length of the conversation.

  “What else did she say?” he asked. The discussion had almost certainly moved beyond a translation of his answer.

  “It’s not important,” Dahlia replied.

  Seth didn’t push her, but he could guess Lana’s next question: It’s not an ordinary part of the life cycle, but now that this one has done it, will you?

  Theo said, “There’s a game I want to play.”

  seth tapped the side of his cart. “Four, minus seven!” Theo shouted.

  “Close,” Dahlia declared encouragingly.

  Seth made the sound again.

  “Four, minus six,” Theo decided.

  “Exactly!” Dahlia started squawking, explaining the outcome to the crowd of spectators. Seth started moving the cart again, backing it up and turning it before driving it forward, so as not to make Theo’s task too easy.

  Iqbal had marked out the grid by scraping lines with a stick on a patch of open ground in the middle of the settlement, then he’d placed Theo at the center. Seth had shouted out the coordinates from two of the corners to get him oriented, but after that it had been up to Theo to judge the positions of every sound that followed.

  “So where am I now?” Seth asked.

  “Two, zero,” Theo said confidently.

  “Two, zero!” Dahlia confirmed, and translated.

  Ada said, “This is ridiculous; he can hear the cart moving from place to place.”

  “So how should we be doing it?” Theo asked mildly.

  “Get three or four Southites on the grid. They wander about at random, then one of them makes a sound, and you have to place it.”

  Seth said, “I’d be happy to withdraw. Dahlia? Can you ask for volunteers, and explain the new rules?”

  He drove the cart off to the side. Iqbal ran in and touched up the grid, repairing the lines that the belts had scuffed, while Dahlia conversed with would-be participants.

  Eventually, Iqbal, Marco and Lana took to the grid. They scuttled around Theo in all directions, throwing up dust and immersing him in a confusion of eight-legged footfalls. Then Dahlia called out to them, they froze, and Lana emitted a brief hoot.

  “Five, three?” Theo said tentatively.

  “Exactly!”

  Dahlia translated the verdict, and the game continued.

  Sometimes Theo was off by one grid square, but never more. Seth was astonished; he’d always known that his Sider’s hearing was superior to his own, but it had never occurred to him that the ability to locate an object in the dark cone by its echo would extend to objects outside the cone that were emitting sounds of their own. However helpful it was for Walker and Sider to share each other’s vision, apparently the Siders had never entirely lost their ancestral talent for deducing the position of anything that made a noise, in any direction.

  Dahlia said, “I want to try it!”

  Ada grumbled, but didn’t refuse. Iqbal took Theo aside, and swapped Ada onto the cart where Seth had been lying; she drove herself to the center of the grid, then Iqbal fetched a small timber screen with one axial edge and propped it up in front of Ada’s face to block her view.

  The Southites went to three corners of the grid and called their positions, then continued the game as before. Dahlia gave her answers in both languages, and at first she did much more poorly than Theo, but by the ninth or tenth try she began to improve.

  “This might actually work,” Seth said quietly. As relieved as he was that the ordeal hadn’t been for nothing, the truth was he felt almost as bad at the prospect of leaving Dahlia alone here as he had at the thought of abandoning Ada. “Could you live with the Southites, as the only one of your kind? Never speaking your own language again? Never having a family? Never sharing the view by light?”

  “No,” Theo admitted. “But my history’s very different from hers. What’s ‘her own’ language: ours, or the Southites’?”

  “If Ada was staying, at least they would have had a chance to come home eventually.”

  Theo said, “Don’t underestimate the power of curiosity, on either side. Just because we’ve got all the measurements we need, it doesn’t mean there might not be another expedition here eventually, if we can think of ways to make the whole thing safer. Or the Southites might decide that they want to go and meet a few more of their cousins, while they still have the chance.”

  “Good luck to them getting up the cliff.” At least their feet would be in the right place to make contact with the surface, even if the direction of gravity was less than helpful.

  Dahlia was shouting out the coordinates exuberantly, right every time now. But the happier she sounded, the more Seth ached at the thought of walking away without her.

  seth had expected the novelty of Theo’s separation to wear off quickly, but the Southites seemed to find his emergence as fascinating as if they’d stumbled upon an entirely new creature. Seth’s skull throbbed as much from the noise of all the squawking onlookers as it did from the aftermath of the act. Once or twice, while everyone else was sleeping, he inserted his fingers into the empty tunnel and probed the wall. It wasn’t bleeding anymore, and when he touched the skin—or whatever it was that lined the tunnel—he felt no pain, but the act was repugnant in a different way, imbued with an overpowering sense that he was violating the proper disposition of things. He was afraid that the ruptured surface might become infected, but equally afraid that it would heal in the wrong way: so successfully, so thoroughly and hermetically that when Theo returned, there’d be no hope of reconnection.

  Whatever pain or doubt Theo was feeling, he kept it to himself. When the glare from the chasm filled the enclosure, Seth watched him sleeping in his strange wooden frame, and wondered what it would be like never to be woken by brightness.

  Dahlia said nothing about her plans, but every day she challenged Theo to another round of the grid-location game, as if she was intent on convincing herself that she’d still be able to help her Southite friends if she chose this new condition. As Seth watched her playing, with Ada’s eyes covered for the duration of the game, it struck him more forcefully than ever just what Dahlia would be giving up. If the glorious panorama of the hyperboloid was mere scenery, light also offered the most natural way to perceive her companions.

  On the fourth day, as usual, Theo played first, standing inert in the middle of the dusty ground. It didn’t seem fair for Dahlia to judge his calls when they were competing, so Seth took on the role, watching from atop a cart so he could see the grid properly.

  Iqbal was joined by two new grid-runners, Reva and Julia. Seth was always amused by the efforts the Southites put into complicating their paths between calls, circling the caller multiple times then spiraling back again, as if the whole trick depended on tracking their motion in detail. Seth would not have put it past Theo to announce the locations of all three runners even if they’d stayed silent when they stopped, but the people on the expedition who were going to be relying on Dahlia’s protection would surely be willing to call out their names to her periodically as they marched across dangerous terrain.

  The runners stopped, and Reva hooted.

  “Six, seven,” Theo called.

  “Not even close!”
Seth ruled, surprised; Reva was at four, one. Dahlia spoke to Reva, who hooted again.

  “Six, seven!” Theo insisted angrily. “No. Six, seven, eight, nine, ten.”

  “Theo?” Dahlia sounded hopeful that he might be joking with her.

  “Six, seven, eight, nine, ten,” he repeated.

  The players and spectators grew silent. Seth said, “We need to get him away from here. Take him to the enclosure.”

  Dahlia translated, and the Southites acted swiftly; Iqbal carried Seth, and Reva carried Theo. In the enclosure, Seth used a scoop to bring water from the trough and pour it into Theo’s mouth. The tiny muscles worked to draw some in, whether by will or by reflex. The chewed mush he’d been imbibing for the last four days had been moist, and he’d never asked for it to be supplemented with water, but he might not have been fully aware of his own thirst, or understood its remedy, the way a Walker would have.

  “Is that better?” Seth asked.

  Theo emitted a long string of gibberish, but the nonsensical words did nothing to diminish the utter weariness in his voice.

  Ada and Dahlia arrived, driving the cart up to the side of the enclosure. Ada said, “You know what he needs.”

  “Yes.” Seth wasn’t going to risk harming him by trying to get him back inside his skull in this state. “Does anyone have a knife?”

  Dahlia hesitated, then called out to the group of Southites who’d gathered nearby. Someone ran off. Seth lay staring at Theo, at a loss as to how he could comfort him without inspeech; ordinary language felt inadequate for the task, like trying to comfort a fellow Walker in distress without laying a hand on them.

  Lana approached, holding a knife. Seth waited for her to pass it to him, already thinking through the geometry; the shaft wasn’t axial, which was a nuisance, but he’d still be able to grip it between his fingers and poke the tip into some part of his skin. But Lana entered the enclosure and walked past him toward Theo.

  “What’s she doing?” Seth demanded, suddenly recalling Martha’s attempt to euthanize him. “Dahlia? What’s she doing?” He crawled after her and grabbed at one of her hind legs, but she pushed him away effortlessly.

  She picked up the water scoop that was sitting on the ground, held it against one of her front legs, and then cut herself with the knife. Seth saw blood trickling out of the wound, red as his own, leaving its color on her matted fur as it flowed down into the scoop.

  “No!” he protested. “He needs mine!” He looked to Dahlia, and she translated his words, but Lana ignored him. When he tried to move between her and Theo, she grabbed him with two free hands and held him at bay.

  Theo started muttering again, his pinger shuddering out confused fragments of words. Lana raised the scoop to his mouth; Seth couldn’t see if he was accepting her offering, but only a few droplets spilled down his body.

  Lana held the scoop to her leg again, and squeezed the flesh to make her blood run out faster.

  “Why won’t she let me feed my own Sider?”

  Dahlia put this to Lana, then replied numbly, “She needs to know what’s possible. If this doesn’t work, then she’ll let you feed him.”

  Seth watched, angry and helpless, as she tipped more blood into Theo’s mouth; all he could do was hope that she didn’t poison him before she accepted that she’d failed.

  Theo shuddered strangely, but then he spoke. “Where the fuck am I? Seth?”

  “We’re in the enclosure. What do you remember?”

  “We were going to play the grid-running game,” Theo replied. His words were a little slurred, but he seemed lucid now. Lana was still pouring from the scoop, oblivious to the meaning of their conversation. “Then I started to feel dizzy. But . . . if you’re over there, who’s giving me this blood?”

  Seth said, “Someone who’s just proved that she really is my cousin.”

  three days after theo returned to the tunnel, Seth was woken by the sound of Ada and Dahlia whispering to each other. He couldn’t tell whether Theo was awake too, so he lay still and tried to fall asleep again. They were both going to need their rest, if the torn connections were ever to be rejoined.

  He succeeded, but only for a while.

  “Seth?” It was Dahlia’s voice, quiet but insistent.

  “Yes?”

  “Will you help us? Please?”

  His eyes were still closed, but the gray light penetrating his eyelids seemed to shift in front of him.

  “What does Ada say?” he asked.

  “We need your help,” Dahlia replied.

  “And I need to hear that from her.”

  Ada spoke haltingly. “I want to stay here with Dahlia.” Seth had never heard so much pain in her voice.

  He said, “You need to agree on this, between yourselves.”

  “She can’t live here!” Dahlia protested. “It’s too hard for her. I understand that now; her body needs to move the way it can in her old home. I’ll be all right. Everyone here is good to me.”

  Seth felt his own body start shaking, but he forced himself to speak calmly. “I understand, but it’s not my choice. You need to agree.”

  Theo said, “Ada?” She didn’t reply. “I can promise you this much: without you, Dahlia will still receive nourishment, and she’ll still always know exactly who’s around her. I might not be smart enough to learn the language, or strong enough to offer to take her place, but I know it won’t be hard for a Sider in the way it would be for you.”

  Ada remained silent.

  Seth wished he had some way of untangling all the things that might be driving her to stay: the bond she’d formed with Dahlia, the guilt she felt about the way she’d lived before, some sense that this was the only way to atone. He said, “Do you want Thanton to change, or do you want life there to go on as it is?”

  “I want it to change,” Ada replied angrily.

  “Then come back, and help to make that happen. Because I doubt there’s anyone in the world more able to do that than you.”

  Ada said nothing, but Seth heard Dahlia whispering to her, repeating one phrase over and over. He couldn’t make out the words, but the rhythm alone was one of reassurance, like a parent soothing a child. Seth clung to the sound, trying to reconcile himself to what was happening.

  Ada let out a cry of anguish, but then she replied to Dahlia, quietly and calmly.

  Seth waited.

  “We need your help,” Ada said. “We need you to help us separate.”

  21

  “Is everything secure up there?” Seth asked anxiously. He glanced toward the line of lights; it was getting close to the departure time.

  “Yes!” Ada called back. “And you can’t fault the Southites for their carpentry. I’d bet you anything that when we disembark, the fruit won’t even be wet.”

  Seth cranked his bench up, away from the storage lockers at the bottom of his box-like section of the hull, raising his body high enough to let him look straight out toward the shore. Dozens of Southites stood by the water’s edge: Lana, Siméon, and Martha were among them, along with all the boat-builders, but many were curious spectators that he had never had reason to name.

  “Do you ever think about the Southites from the other chasm?” he asked Theo. “If our lot win, what happens to them?”

  “They’d better get creative, and learn to negotiate. They must have something to offer a collaboration.”

  “I hope so.” Seth could only wish them well, with no sense that he was leaving the problem behind. His own hyperboloid was going to have to deal with the same kind of competition for resources, as the migration squeezed past the hole.

  He described the crowd to Theo. “Iqbal and Dahlia are at the front; she’s in that tall frame that holds her up above his back.”

  “There’s something I can be thankful for,” Theo replied.

  “What?”

  “At least I don’t have to stare at your body all day long.”

  “It’s her choice,” Seth said. “Orange fur, or a tiny patch of dir
t.” He laughed. “I think Dahlia must have overheard you.”

  “Why do you say that?”

  “Iqbal’s started juggling stones.” He was tossing them high into the air with one hand and trying to catch them with the opposite one. He wasn’t doing a bad job—and whether or not Dahlia had found some way to give him cues fast enough to help, it would certainly break the monotony of her view.

  “Are we going?” Ada asked impatiently.

  “We’re going.” Seth gazed at Dahlia for a moment, glad that she couldn’t see his face. “Be happy!” he shouted. “Be safe! Stay warm!”

  “You too,” she called back.

  Seth waited to see if Ada had some last words for her, but the two of them must have said their goodbyes. He reached over for the lever that engaged the runners, and lowered them into the water. The flow started up, brisk and steady, and the boat began moving away from the shore.

  He looked up at the blue-gray bowl, hunting for the navigation cues he’d need to find his way to the northbound current. Then he looked back to the shore, where the Southites were hooting and squawking. Dahlia was almost invisible now; he could just make out the slender beams of the pyramid that held her.

  He raised one of the runners, letting the boat turn three-quarters of the way toward the blackness of the chasm. The journey ahead remained as daunting as ever, but they were as rested and well supplied as they could have been. “I can’t wait to fucking walk again!” he called up to Ada. “Even with a stilt.”

  “Yeah.” Ada’s voice was somber.

  “Are you all right?” Seth asked.

  “I’ll live.”

  Seth didn’t have it in him to keep insisting that she’d done the right thing. “Dahlia will be happy,” he said. He believed that much. Even if most of the Southites thought of her as merely useful, at least one of them genuinely cared about her.

  “She told me she knew we weren’t her parents,” Ada said. “She made it sound as if she was the one who should have been embarrassed, for ever assuming something so childish and naïve.”

  “But it’s good she’s clear about that.” Seth watched the chasm growing nearer, as the last traces of light abandoned it. “Did she ask about her real parents?”