Dichronauts

by Greg Egan

  “So do we hide the instruments and limp into town, claiming to be stragglers who survived the same attack?” Sarah wondered.

  Judith said, “I vote we don’t announce ourselves at all, until we’ve done a bit of surreptitious reconnaissance.”

  “The problem with that,” Theo replied, “is that if we’re caught, we’re far more likely to be treated badly.”

  “If we do it in the early hours of the morning, we’re not likely to be caught.”

  Seth said, “If we do it in the early hours of the morning, what will it tell us? What would we learn about our friends by wandering the streets of this town while everyone’s asleep?”

  “So we go in early, and see if there’s a vantage point,” Judith decided. “A place where we can stay hidden during the day, and watch what unfolds.”

  Theo was unimpressed. “Of course: we’ll just follow the signs pointing to the special viewing platform that every town constructs for the benefit of wandering spies.”

  Sarah said, “It wouldn’t hurt to take a closer look before we commit to showing ourselves.” She glanced at Seth with a somber expression conveying what none of them wanted to say: if their friends were dead at the hands of these people, the sooner they knew that for sure, the less chance they’d face of sharing the same fate. “But we shouldn’t risk everything on this. Only one pair goes in.”

  “All right,” Theo said reluctantly.

  “And we toss for it,” Seth insisted.

  They had no coins, but after scrabbling on the ground for a minute they managed to find a small, flat stone that was symmetrical enough to be fair without its sides being indistinguishable. Sarah tossed it, Seth called, then they both took a step to the south so their Siders could see how it had fallen.

  at the point where Seth reached the river, it ran from the south-south-west. The darkness was impenetrable, but Theo’s pings—wide to the north, cautious to the south—guided him well enough to let him move along the bank with confidence. The view to the north was not redundant: seeing the part of the river he’d just passed gave the tentative peek ahead valuable context, without which he would have felt about as secure as if he were groping his way forward by touch alone.

  «Lucky we got in so much practice at Lida,» Theo said.

  «Except at Lida, we couldn’t swim into town.»

  Theo hesitated, unsure whether he should take this threat seriously. «You really think you could go against the current?»

  «Not a chance,» Seth confessed. As he’d marched across the desert he’d fantasized about it, but if he’d actually dived into the river he would probably have ended up at the waterfall instead.

  «With a boat, maybe,» Theo mused. «If you gave it steep enough runners, you might be able to drive it upstream.»

  Theo’s peek to the south revealed an irrigation canal branching off from the river, just in time to keep Seth from stumbling into it. He squatted down at the edge and dipped one foot into the water; it was shallow enough, and sufficiently slow moving for him to wade across—but chilly enough to kill off all further thoughts of deliberate, prolonged immersion.

  As he trudged across the muddy edges of the fields from canal to canal, Seth tried to keep track of his progress against the overall sense of the scale of the city that he’d formed from the distant view by daylight.

  «Do you remember that geography class when they gave us a formula for agricultural land use as a proportion of a city’s total area?» he asked Theo.

  «No.»

  «No?»

  «Some of those lessons were as boring for me as they were for you,» Theo replied. «If it was so important, you should have paid attention yourself.»

  «Fair enough.» Seth tipped his head to the west and caught a flicker of lamplight reflected off the river, though the path directly to the source appeared to be in his dark cone. «Forget about the formula, I think we’re getting urban right now.»

  A minute later he could see half a dozen lamps on the far side of the river, and as his eyes slowly made sense of the dark shapes between them, it was clear that he was staring at closely spaced buildings, not scattered farmhouses. He slowed his pace and looked back to the east, prepared to enter the city itself.

  A single lamp appeared at the southern edge of his vision, then Theo showed him the cobblestones moments before they met his feet. Seth paused and tried to make sense of his location; he seemed to be at the end of a narrow road that ran down to the riverbank. «A little more to the south,» he begged Theo. Theo obliged, pinging progressively farther until he revealed a high wall, the side of a large building blocking the way.

  Seth found the corner of the building nearest to the river, but there was no prospect of squeezing past there: between water and wall there was nothing but waist-high reeds in treacherous mud. He walked slowly east down the road; Theo retracted his pings to just a pace or so in both directions, but there was enough scattered lamplight to keep them from being entirely blind.

  Dawn was still hours away, and Seth could hear nothing but the lapping of water on the riverbank. After a while he came to a crossroads, signaled by a change in the orientation of the paving stones. He sidled south, peering into the darkness to the east and managing to discern a row of houses beside the road.

  «All of this had to come from somewhere,» he said. «It didn’t just rise out of the desert by magic.»

  «Maybe they’ve always been close to the forest,» Theo suggested. «And when it started drifting, they followed it.»

  Seth pictured their unreliable map. «There was a town called Thanton north-west of the forest. But once they learned about the river, they might have come this far south.» As far as he could recall, the most recent travelers’ accounts of the town that had made their way to Baharabad were from a couple of generations ago. If Thanton had been known for its fearsome inhabitants that would surely have stuck in his memory—and merited some discussion at the expedition’s briefing—but after so much time had passed it wasn’t safe to assume anything, especially now that these people had a river to defend.

  He sidled on down the dark street, passing three more crossroads before the character of the buildings around him began to change. Though he was struggling to interpret slabs of gray that he could only just distinguish from the background, the shift to more imposing structures was unmistakable. A grain store? A bath-house? A meeting hall? He was tempted to ask Theo to ping everything to the south and prove that they’d reached the center of town, since they were probably far enough from any private residence to avoid waking a single Sider, but that would be foolhardy. What he needed to do was find a hiding place and lessen his risk of discovery, not increase it.

  Seth began exploring east-west side roads, and Theo cautiously pinged the objects they passed. There were three large bins behind a restaurant, unmistakable from their odor of rotting food scraps, but though the space between these containers and the wall might have made a good site to avoid detection for a while, there was no way of knowing when and how the bins would be emptied, and the chances of learning anything vital from the gossip of kitchen hands dumping vegetable peel seemed slim.

  «Forget this,» Theo said. «I know the perfect spot.»

  «Somewhere we passed?»

  «I’m not sure. But it must be close by.»

  As it turned out it wasn’t far, but it still took them what felt like an hour of pursuing dead ends before they found the bridge. Seth clambered awkwardly over the guardrails along the eastern approach, then trudged around the muddy edges of the riverbank to a point behind a supporting column where he would be out of sight to anyone up on the street. He sat on the sloping ground, his head tipped so he could watch the river. If a barge went by—or a brave swimmer—he would need to retreat even further behind the column, but he wasn’t going to do that preemptively and leave himself vulnerable to being cornered if someone approached on foot.

  «Are you sure you’ll be able to hear people talking?» he asked Theo. In Baharabad it was co
mmon practice to dawdle on the bridges when chatting with friends, but the river here sounded loud enough to drown out any conversation, and once the planks above were creaking with footsteps that would only make the task harder.

  «You have no idea,» Theo boasted.

  «I don’t,» Seth conceded. «I can see what you see . . . why can’t I hear what you hear?»

  Theo thought for a while. «Maybe you’re just not equipped to make sense of such detailed sounds. Knowing about an object in your dark cone isn’t really any different from knowing about an object right in front of you: it’s exactly the same kind of thing out in the world. But even there, what we learn from each other is limited: I can’t glean colors from what you share with me, and you can’t perceive textures the way I do. And it’s not that either of us is holding things back. We just don’t have space in our minds for the kind of details we can’t see for ourselves.»

  «Right.» Seth could recall occasions when Theo had tried to point something out to him by referring to the roughness of its surface, as if that were meant to be obvious from afar, and no doubt he had committed the same kind of gaffe himself with hues. Over time they’d adjusted their expectations of each other without thinking about it too much, but it was still easy to forget that the world inside Theo’s skull was not the same as the world inside his own.

  The riverbank was damp and chill as they waited for dawn. Seth heard the first footsteps overhead before the sky was light, but these early risers walked alone, some empty-handed, some struggling with heavy loads. There was even the rhythmic squeak of a wheeled cart, but no conversation.

  Gradually, the town began to stir, with shouts and laughter in the distance, then finally some murmurs from the bridge itself.

  «What are they saying?» he asked Theo.

  «They’re arguing about a debt.» Theo sounded tense.

  «Why is that so worrying?»

  «It’s not,» Theo replied irritably. He was probably just straining to hear, and could have done without being pestered for a running commentary.

  As the morning wore on, Seth watched the light on the river, wishing he could contribute more to the endeavor. He tried to picture the owners of each set of footsteps from their gait, but that was just a game, and even when they raised their voices in anger or mirth, the words were so muffled—or the accents so thick, the dialect so foreign—that he barely understand half of what was spoken.

  Theo said, «Have you noticed anything strange?»

  «I’ve barely noticed anything ordinary.»

  «How many Siders have you heard so far?»

  «I have no idea,» Seth replied. If he heard clear speech in a familiar accent, he could usually distinguish between the characteristic timbres, but whatever the cues were here, he was oblivious to them. «Ask me something easy, like how many of the Walkers were missing a leg.»

  «I haven’t heard one,» Theo declared. «Not on the bridge, not from the streets around us. Not one Sider has spoken, this far into the day.»

  «Maybe there’s a custom here that they get to sleep late,» Seth joked.

  «They’re pinging,» Theo said.

  «Are they pinging us?» Seth asked, alarmed.

  «No, but I can hear that they’re pinging the bridge.»

  «How many people have you heard talking?»

  «Dozens.»

  Seth was perplexed. «Could their sounds be different from yours? I mean . . . could you just not be hearing them, the way I can’t hear it when you speak with another Sider, out of my range?»

  «Even if they possess some freakish talent that lets them use pitches I can’t hear, why aren’t they talking to the Walkers? I can’t believe the Walkers would share the same skill.»

  «No.»

  Theo said, «They must have done something to them.»

  «What do you mean?»

  «Harmed them. Crippled them.»

  The revulsion in Theo’s voice left no doubt that he was convinced, but to Seth the conclusion seemed fanciful. «That makes no sense,» he replied. «If the Siders have been harmed to the point where they can’t speak, why would they still be pinging?»

  «I don’t know what kind of injury’s been inflicted on them,» Theo said. «But half the people around us are mute. That’s not down to chance.»

  Seth had no counter-explanation to offer, but the precept that declared it a shameful aberration to mistreat your Sider was hardly some cosmopolitan affectation that tough-minded frontier folk would be free to discard. How could a whole town survive, if the practice became routine? A Walker who lost their temper and jabbed at the parasite in their skull just ended up side-blind.

  Theo said, «I want to try something.»

  «What?»

  «Next time there are footsteps above us, I want to shout “stop!” in the Sider language and see what happens.»

  Seth shifted uncomfortably on the sand. «Do you think that’s a good idea?»

  «We need to know,» Theo insisted. «This isn’t idle curiosity. If we have a chance to communicate with Aziz and Amina without anyone overhearing us, that could make all the difference.»

  «But what if you’re wrong, and you give away our presence?»

  «One word might make people stop and look around—but they’re not going to climb over the rails and traipse through the mud just because they weren’t sure where a shout came from.»

  Seth said, «They might, if it’s as rare for a Sider to speak as you say it is.»

  «If it’s as rare as I think it is,» Theo countered, «no Walker will ever learn of it.»

  «Maybe.» If the Siders had been cowed into silence, they weren’t going to betray another Sider to their oppressors. «All right. Just make sure you’re listening carefully to the aftermath, so you can tell me which way to run.»

  Seth rose into a crouch, ready to flee along the riverbank if necessary. Footfalls sounded, planks squeaked; when he looked up directly at the underside of the bridge, he could see the timber beams shifting slightly. But the Walker continued on, without so much as a pause.

  «Did you do it?» he asked Theo.

  «Yes.»

  «How loudly?»

  «Like a matter of life and death. Either the Sider didn’t hear it, or they didn’t tell the Walker, or the Walker didn’t care what the Sider said.»

  Seth considered these three possibilities. If it had been the last, they’d hardly be safe to roam the streets at night yelling out Aziz and Amina’s names. «You want to repeat the experiment, with different words?»

  Theo said, «You read my mind.»

  Commands, pleas for help, insults, and warnings all had the same effect: none at all. It seemed unlikely that a dozen different Walkers would have reacted with indifference to such interjections if they’d actually known about them.

  Seth was cheered by the prospect of exploiting the discovery, however disturbing Theo’s theories about the underlying reason. And he didn’t want to try to guess what was really going on, while crouched under a bridge, unable to ask a single citizen of Thanton for their own account. Perhaps in Elena’s angriest moments she’d wished for a world in which all Siders were voiceless, but you couldn’t run a town on the darkest urges of its most miserable children.

  He stared out across the river and tried to stay alert, without distracting Theo with needless chatter.

  it was mid-afternoon before Theo had anything more than an absence to report, but the revelation was worth the wait.

  «“When’s the Council going to decide what to do with the diplomats?”» Theo quoted one of the bridge-crossers as saying; the words had been nothing but muffled burbling to Seth’s ears. «To which the answer was, “Tomorrow night.”»

  «So they’re here? They’re not lying injured in the forest somewhere!» Seth barely managed to keep himself from shouting in jubilation. «Are you sure it was “do with the diplomats,” not “do about”?»

  «Yes,» Theo said flatly.

  «Maybe that’s just a difference in dialect? Do wit
h, do for, do to . . . this far from Baharabad, who knows what preposition means what?» Theo didn’t reply. Seth said, «So we have a day and a half to find them, before something’s done.»

  «To find them, and release them,» Theo corrected him.

  Seth felt the muscles in his back squirming in rebellion at the thought of remaining where he was for another second; the news that Thanton’s hospitality toward strangers was now as suspect as its treatment of its Siders only left him more ashamed than ever at the prospect of cowering under the bridge until dark.

  «Do you think there’s any chance that we could pass for locals?» he asked Theo. «This town isn’t so small that everyone would recognize everyone else.»

  «My part would be easy,» Theo replied dryly. «But do you think you could fake the accent?»

  «I wasn’t planning on actually talking to anyone.»

  «That might not be an option. And what about your clothes?»

  Seth had no reply to that. Apart from a general travel-worn shabbiness, it was possible that the style alone would mark him out instantly as a stranger.

  «We need to see some of these people,» he declared. «For all we know, they might have two heads.»

  Theo said, «Two heads is normal, by my count. But I’d say they only have about one and a quarter.»

  Seth rose to his feet and moved cautiously to the edge of the column. He peeked out across the river at a road that ran beside the opposite bank. It wasn’t easy to make out the details of people’s apparel from this distance, but after a while it was clear that the colors were all brighter than his own, the sleeves shorter, the hems of the shirts lower. As far as he could tell from their body language, merely passing someone on the street didn’t always entail an exchange of greetings. But the fact remained that, at the very least, his dull, oddly cut clothing would attract attention before he said, or declined to say, a single word.