Teranesia

by Greg Egan

  ‘Are you sure it’ll take your weight?’

  The next branch above him was barely chest high now. He wrapped his arms around it and lifted his feet off the one below. ‘Yes, I’m sure.’

  He clambered up. He had a firm hold and a secure footing, but he could feel the top of the tree swaying, and the branches around him had thinned enough to make him feel exposed. Looking sideways through the forest at this level, the distant branches appeared uncannily like the struts for some elaborate geodesic folly. Maybe the Stetsoned entrepreneurs who’d followed the expedition down from Ambon could anchor a perspex roof to all this scaffolding, and turn the whole island into an exhibition centre.

  He looked down and saw the ruins of the kampung.

  A wave of vertigo swept over him, but he kept his grip on the branch beside him. The centre of the kampung had been reclaimed by the forest, but the trees couldn’t quite obscure the roofs of the huts: the matt-grey photovoltaic surface was still visible through a thin layer of creepers. The buildings had all become badly skewed, but none of them appeared to have collapsed completely. The six huts had been arranged in a regular hexagon, and in their current state he couldn’t tell them apart; with the path from the beach erased there were no cues to enable him to orient the view.

  He looked away, remembering his purpose. There wasn’t much foliage around him, but he examined it dutifully. Then he spoke into his notepad.

  ‘There’s nothing else here. I’m coming down.’

  Three more trees yielded five more pupae, but still no sign of the larval stage. It was mid-afternoon; Grant decided there was no point looking further. Prabir was dripping with sweat, and itching from all the contact with bark and sap. When they reached the beach, he handed his samples to Grant and swam out to the reef and back. After the heat of the forest, the water was glorious beyond belief.

  He collected his clothes from the beach and waded back to the boat. As he climbed up on to the deck, Grant met him with the latest news from Brazil. ‘They’ve copied whole, purified pigeon chromosomes, using just SPP,’ she said. ‘And the error rate was the same as mine, for the cultured cells.’

  It took Prabir a moment to interpret this result. ‘So there is no second protein after all?’

  ‘Apparently not,’ Grant concurred. ‘SPP alone in a test tube does just as good a job as SPP in an intact cell, if and only if the sequence being copied is the same. Which shows that these changes aren’t errors at all. Or at least, they’re not just random copying mistakes. They must depend in some way on the sequence itself.’

  Prabir pondered this. ‘The pigeon genome has probably been copied in the presence of SPP dozens of times. So whatever transformation SPP causes must be convergent: the genome must change less and less with each iteration, until by now it’s virtually stable under the process.’

  Grant nodded. ‘Whereas there’s no reason at all why the test sequences they first tried copying would have been stable. Randomly chosen input sequences would have undergone apparently random changes.’

  Prabir had a minor epiphany. ‘And all the different fruit pigeons on Banda that ended up looking identical – the process must also be convergent for sufficiently similar genomes. Not only is there a stable endpoint for a given starting point, but similar starting points – closely related species – get dragged towards the same endpoint.’ He beamed with delight. ‘It all makes sense!’

  Grant was pleased, but slightly less rapturous. ‘Except we still don’t know what SPP actually does, or how it’s doing it.’

  ‘But the Brazilians have all the information they need to crack this now, don’t they? They just have to look more closely at their model.’

  ‘Maybe. For a molecule as large as a protein you can never solve the equations for its shape and binding properties exactly, and it can be hard to choose a set of approximations that only cause trivial discrepancies. They’ve already tried simulating the pigeon chromosome being copied by SPP, and the simulation produced exactly the same error rate as for any other sequence.’

  Prabir winced. ‘So their model has just proved that it’s missing the most important subtlety of the real protein.’

  Grant didn’t see it quite so bleakly. ‘Missing it now, but they might yet be able to capture it with a little fine-tuning. At least they know what they’re aiming for, what they need to get right.’

  Prabir said, ‘OK. So what do we do next?’ Grant had been posting all their results on the net, stating precisely where they’d been collecting their samples; the expedition biologists would already know that there was no need for anyone else to come here. So long as Grant didn’t cut corners.

  She said, ‘I’ll have a proper look at these pupae, see what that tells us. I don’t know whether it’s worth going back to hunt for the larvae; I mean, the life cycle is of interest in itself, but larvae don’t make germ cells.’

  Prabir filled a bucket with sea water and set about washing his sap-stained clothes, while Grant went for a swim. The travel shop in Toronto had sold him a detergent with enzymes that worked in the presence of salt; as long as you didn’t leave it too late you could remove almost anything with the stuff.

  When he walked back into the cabin to get fresh water for rinsing, he glanced at the wire cage holding the adult butterflies they’d captured.

  There was a pupa, similar to the ones he’d collected in the forest, hanging from the top of the cage. Except it couldn’t be a pupa. The adults had only been there for a day; at most they might have laid eggs. Grant had been in the cabin twenty minutes before. This had happened since then.

  Prabir counted the adults. One of them was missing.

  He ran out on deck. ‘Martha! You have to see this!’

  She was halfway to the reef. ‘See what?’

  ‘The butterflies.’

  ‘What about them?’

  ‘You won’t believe me if I tell you. You have to see it for yourself.’

  Grant turned back towards the boat. She followed him into the cabin, dripping. Prabir watched her expression go through several changes.

  He said, ‘There’s something I’ve been wanting to try, if you’ll let me.’

  ‘I’m listening.’

  He picked up one of the dormant adults he’d taken from the forest. ‘This insect hangs there, looking like a nutmeg fruit, unable to fly away. So presumably it has some defence: it must smell bad, or taste bad, to the birds that would otherwise want to eat it on sight.’

  ‘Presumably.’

  Prabir approached the cage where they’d placed the fruit pigeons, and gave Grant a questioning look.

  She said, ‘Go ahead, please. I want to see this too.’

  He opened the door just wide enough to toss the dormant adult on to the floor of the cage. All of the fruit pigeons rushed forward; one of them managed to shoulder the rest aside and grab the insect. The bird stretched its jaws to their full extent and swallowed the sleeping butterfly whole.

  Grant sat down heavily on one of the stools. After a long silence, she declared, ‘Maybe there’s a parasitic larval stage. Maybe the adults don’t lay their fertilised eggs; maybe they’re incubated inside the pigeons, after the adults act as a lure.’

  ‘And that’s why we’ve seen no larvae?’

  ‘Maybe.’ Grant stretched her arms and leant back on the stool. ‘I suppose it could burrow out through the skin, but I’m beginning to have visions of sifting through a large pile of pigeon shit.’

  Prabir walked over to the butterfly cage. They’d placed some foliage in the bottom, but there’d been no elevated twigs or branches from which the would-be martyr could hang itself. He squatted down to try to get a better view of it, and saw a long string of dark-grey beads sticking to the underside of one of the leaves.

  He said, ‘Was this foliage clean when you put it in the cage?’

  ‘I believe so. Why?’

  ‘I think I’ve just found some butterfly eggs.’

  Prabir lay awake, listening to the waves brea
king on the reef. The eggs would allow them to observe every stage of the butterfly, but that still wouldn’t be enough. The butterfly’s genome would be stable now; only samples from the kampung could show the way the São Paulo protein had changed it, from generation to generation, twenty years before. They needed to extract every clue the island held; if they didn’t finish the job properly, the expedition would follow them here.

  He went into the cabin and woke Grant, calling out to her from the doorway. Her bunk was hidden in shadows, but he heard her sit up. ‘What is it?’

  He explained what he’d seen from the treetops. ‘I know where it is now. I can get to it from the beach.’

  She hesitated. ‘Are you sure you want to do this? You could draw me a map, I could go by myself.’

  Prabir was tempted. The place meant nothing to her: she could walk in and take whatever she needed, ransacking the site unflinchingly, immune to its history.

  But this was his job. He couldn’t claim to be sparing Madhusree the pain of returning, only to hand the task over to a stranger.

  ‘I’d rather go alone.’

  Grant said decisively, ‘We’ll go together, first thing tomorrow. I promised you after the mangrove swamp: we won’t get separated again.’

  12

  Prabir took comfort in the usual routine: wading to the beach, insect repellent, mine detector checks. Looking back at the reef as he pulled on his boots. They’d gather some samples and return to the boat. It would be a day like any other.

  He’d estimated GPS coordinates for the kampung, from his notepad’s log of its position the previous day and his recollection of the treetop view. They picked their way laboriously through the shrubs; this was the first time they’d had no choice about their destination, no option of taking an easier route. Grant had once tried clearing a path in the undergrowth using a parang she’d bought in Ambon, but it had been a waste of effort; the machete was perfect for chopping through occasional vines, but the knee-high thicket was too tangled, there were too many strands to sever.

  Grant was unusually quiet; she might have done this easily enough alone, but his presence must be making her feel more like a trespasser. Prabir said, ‘You wouldn’t believe it only took me half an hour a day to maintain this path.’

  ‘That was one of your jobs?’

  ‘Yeah.’

  She smiled. ‘I thought I was hard done by having to clean the bath. And at least I had somewhere to spend my pocket money. I suppose you got paid in net privileges?’

  ‘I don’t remember.’

  Prabir’s eyes kept filling with sweat. As he wiped them clear, he could almost see the approach as it had once been. He’d heard the thud of the mine and raced towards the kampung with Madhusree in his arms. Sailing past the trees ever faster, as if he was falling.

  Grant spotted one of the huts before he did: it was leaning precariously, covered in fungus and lianas. Unlike the roofing panels he’d seen from above, the walls were stained and encrusted to the point where they might as well have been deliberately camouflaged. Prabir was suddenly much less sure that they’d followed the old path; he didn’t expect the hut to be recognisable, but its position was not where he’d imagined it. Maybe they’d taken a different route entirely, one that had always been uncleared jungle.

  Even when they were standing at the edge of the kampung, it took him a while to find all six huts amid the trees. He said numbly, ‘I don’t know where we are. I don’t know where to start.’

  Grant put a hand on his shoulder. ‘There’s no rush. I can look inside one of these buildings and describe it for you, if you like.’

  ‘No. It’s all right.’ He turned and walked towards the hut on his right. The doorway facing the centre of the kampung was hidden beneath a dense mat of creepers, but the walls had split apart at one corner, leaving a gap that made a much easier entrance.

  Grant came after him. ‘You need a torch, and we need to do this slowly. We don’t know what’s in there.’

  Prabir accepted the flashlight from her. She unslung her rifle and followed behind him as he ducked down to enter the hut. Enough soil had blown in, and enough sunlight came through the gap in the walls and the vine-draped windows to cover the floor in pale weeds. There was a hook on one wall, and the cracked, shrivelled remnants of a rectangle of canvas curled up beneath it.

  He said, ‘This was mine.’ He gestured at the hammock. ‘That was where I slept.’

  ‘Right.’

  Termites must have devoured the packing crate where he’d kept his clothes, once the preservative had leached out of the wood. The hut looked barer than a prison cell now, but it had never been full of gadgets and ornamentation; all the possessions he’d valued most had been stored in his notepad.

  He’d looked out at night from this hut, his stomach cramped with anxiety. And then he’d thought of an act that would justify everything he was feeling: a crime to match his sense of guilt, an alibi to explain it.

  Guilt about what, though? Had he stolen something, broken something? What could be worse than sabotaging his parents’ work?

  ‘The butterfly hut.’ He backed out, then tried to orient himself. ‘It was straight across the kampung.’

  He threaded his way between the trees, with Grant walking beside him in silence. It was the most direct route, but he lost sight of the surrounding huts, lost count of their position in the circle.

  The door had fallen off the hut he approached, leaving an entrance curtained with creepers. Grant handed him the parang and he slashed them away. Then he pointed the flashlight into the darkness.

  Madhusree’s plastic cot was covered in fungus, warped and discoloured but still intact. Behind it, his parents’ folding bunk was strewn with debris, the foam mattress rotted, the metal frame a shell of corrosion.

  He’d been afraid for them. Afraid the war would reach them, in spite of the island’s obscurity, in spite of his father’s reassurances.

  But why would he feel guilty? Why would he imagine that he’d be to blame if the war came to the island? Even if he’d fought with his parents and wanted them punished – even if he’d shouted from the slopes of the volcano that he’d wanted them dead – he’d never been superstitious enough to believe that his wishes would be granted.

  Prabir said, ‘Wrong hut. It’s the next one.’

  One wall of the butterfly hut had collapsed outwards, leaving the two half-supported roofing panels to swing down almost to the ground. The result was a rickety triangular prism, with a narrow space between one standing wall and the tilted roof through which Prabir could just squeeze. Grant followed him.

  The wall that had fallen had borne the hut’s windows and door, and the soft forest light hit the gaps in the structure at the wrong angle to penetrate the darkness ahead. Prabir played the flashlight beam along the floor, looking for signs of the lab bench, but the wood had all gone to termites and fungus. The hut was knee deep in twigs and rotting leaves, debris that had blown in and never found its way out again.

  In the far corner, two yellow eyes caught the beam. There was a python, maybe half the size of the one in the mangroves, coiled on top of a pile of litter. Prabir felt his legs turn to water at the sight of it, but he didn’t want it killed unnecessarily.

  ‘Maybe we can work around it,’ he suggested. ‘Or drive it out with sticks.’

  Grant shook her head. ‘Normally I’d agree, but right now we can do without the aggravation.’ She raised her rifle. ‘Stand aside and cover your ears.’ She dropped a pinprick of laser light between the snake’s eyes, then blew its head off. Clumps of white fungus rained from the ceiling. The snake’s decapitated body twitched and rose into a striking position, uncoiling enough to reveal a clutch of fist-sized blue-white eggs.

  Grant held the flashlight while Prabir sifted through the mess on the floor. It was slow work, and the humid air above the decaying leaves was suffocating. When he found the metal stage of his father’s microscope he gave up all pretence of being in control and let
tears of grief and shame run down his face.

  He knew what he’d done. He knew why he’d poisoned the chrysalis, he knew what he’d needed to hide.

  He’d killed them. He’d brought the plane to the island, he’d brought the mines.

  It was too much to face. He couldn’t live, staring into that light – but he’d lost all power to avert his gaze, and every lie he’d held up as a shield was transparent now. He had to let it melt him, he had to let it burn him away.

  He was determined to find the specimens first; they were the last things left that he could hope to salvage. Grant stopped asking him if he wanted to rest or swap positions. Beetles and pale spiders fled as he plunged his hands into the leaves, again and again.

  He pulled out a slab of light, cool plastic, thirty centimetres wide, covered in filth. He wiped it on his jeans. It was an adult butterfly, embedded in something like lucite. An adult from twenty years ago, with the old concentric green-and-black stripes.

  Grant said something encouraging. Prabir nodded dully. There was a bar code engraved in the plastic; any pigmentation it had once held was gone, but the ridges still felt sharp, the code could still be read. The numbers wouldn’t mean a lot without matching computer records, but they’d probably be sequential. He delved around in the same spot, and his fingers hit another slab.

  They left the hut with twelve preserved specimens: eight adults and four larvae. Prabir looked around, getting his bearings.

  He turned to Grant. ‘You might as well go back to the boat now. I’ll follow you in a little while.’ He handed her his backpack, in which they’d placed all the specimens. She accepted it, but remained beside him, waiting for an explanation.

  He said, ‘I want to visit my parents’ grave.’

  Grant nodded understandingly. ‘Can’t I come with you? I don’t want to intrude, but we should be careful.’

  Prabir pulled his shirt over his head, mopped his face with it, then held it bunched at his side to conceal his hand as he switched off the mine detector. He tried to compose his face into an appropriate mask.