Poseidon's Wake

by Alastair Reynolds

  Kanu could not begin to see where this was headed.

  ‘The mere existence of this message would be surprising enough,’ his shadow-self continued, ‘especially as the message is framed in human terms, for human comprehension, because there should not be anyone out there to send a message in the first place! But there’s a deeper mystery here, and a direct reason why the message is of specific interest to our friends on Mars. They think another machine may have sent it. And the likely identity of this artificial intelligence should be of specific interest to you as well since there’s a strong family connection. Do I need to spell it out?’

  ‘Eunice,’ Kanu breathed.

  He remembered the exhibition in Lisbon, the construct simulation of his great-great-great-grandmother, enthroned in glass. Except what he had seen was a copy of a copy, not the construct itself. According to the annotation, nobody was certain what had become of the real thing.

  ‘If you believe the rumours,’ the speaker went on, ‘the actual construct – the illegal, unlicensed artilect emulation of Eunice Akinya – hid aboard one of the holoships and travelled to Crucible. Then, shortly after the settlement, it disappeared again. The rumours – as before, make of them what you will – say that it was abducted by the Watchkeepers, spirited away into interstellar space, or taken as part of some agreement in exchange for the settlement and exploration of Crucible. Either way, there is a direct connection to the aliens. And now something pops up around Gliese 163, but instead of announcing itself to the universe, it chooses to communicate only with Crucible.’

  The figure shifted in the chair. ‘I don’t know about you, but I put some stock in those rumours. Our other mother – one of our other mothers, anyway – was also involved in that supposed business with the Watchkeepers. They took Chiku Green with them, too. Surely that holds some significance for you? Anyway, the Evolvarium has declared an interest. The collective consciousness of the machines must now confront the possibility that there may be another artificial intelligence out there, an artilect old enough to predate the fall of the Mechanism. Furthermore, it’s woven around the personality of the woman who might have single-handedly initiated the Evolvarium. Machines don’t believe in gods, Kanu – but if they did, she’d be a good candidate. Naturally, they’d like to know what’s happening around Gliese 163. That’s where we come in.’

  ‘We?’

  ‘Your injuries were definitely the unfortunate result of terrorist activities, but the incident also provided an opportunity. You are still who you were, but you now serve two masters. When the machines remade your nervous system, they encoded a tiny part of themselves into you. Not via implants – that would have been much too crude and easy to detect – but via the actual topological map of your idiosyncratic connectome. There has always been great redundancy in the human brain, Kanu. Now some of that redundancy has been co-opted, given over to the Evolvarium. You are carrying part of it inside you, influencing your actions and intentions. Influencing, not determining – you still have free will, but the epicentre of your sympathies has shifted. You have not turned traitor to the human species, but from now on the interests of the machines will be of equal importance to you. You stand between two worlds, Kanu.’

  Kanu felt an immediate and visceral revulsion, but also a kind of relief that he now had an explanation for his sense of dislocation. He was neither mad nor traumatised – or no more than might be expected given his ordeal.

  But what had been done to him was still profoundly wrong.

  ‘Here’s the important thing,’ the speaker said. ‘This state of affairs was not forced upon you. It was arrived at by mutual agreement. During the early stages of your recuperation – long before you remember coming back to consciousness – Swift explained to you the nature of the crisis, how the message relates to the machines, and the Watchkeepers, and our ancestor. How they are anxious to know more – anxious to respond – but cannot share this information with the conservative, machine-phobic governments of the solar system. Swift suggested a solution: use you as the means for the machines to extend their influence beyond Mars. You become their vehicle and their agency, Kanu. Both of you understood that it would be the end of your diplomatic career. But that was actually a blessing, as it would hasten your return to Earth – and make it possible for you to set in motion the second part of the plan. Europa is the key. Europa has always been the key. You only had to find a way to get here, a way to get under the ice. But you had already solved that particular problem on Mars. You just needed to reconnect with Nissa Mbaye, to whom you’d once been married . . .’

  *

  They broke through the crust on schedule. He was sitting with Nissa on the command deck, waiting as the radar began to detect the imminent transition from ice to water.

  ‘Suitably refreshed?’ Nissa asked.

  For an instant, Kanu hesitated on the verge of confession.

  It would feel good, to unburden himself – to submit to her understanding and forgiveness. But if his newly uncovered memories were correct, he had come here for a reason. If his confession forced Nissa to turn back, he would have learned nothing about himself, nothing about the grander objectives of the machines. He had to keep the truth hidden for a little longer.

  ‘As a matter of fact,’ he answered, despising himself, ‘I’ve never felt better.’

  ‘Good, because the clock’s been ticking since we landed. I’m testing the law but I don’t want to break it, especially with that heavy Consolidation presence in orbit. To be back on the surface within the agreed window we’ll need to allow enough time to chew through the ice again.’ She was working the controls, preparing for the shift from tunnelling machine to submarine. ‘We’ll be going fast and deep, and we need to cover a few hundred kilometres to reach our objective.’ She looked at him with sudden eagerness. ‘What’s the deepest you’ve ever gone on Earth? Ten kilometres, maybe?’

  ‘Only as a passenger. A lot less under my own power.’

  ‘We’re going down much further than that – more than a hundred kilometres of vertical descent. I know that sounds impossible, but this is Europa, not Earth, and the pressure builds much more slowly. We’ll top out at about two hundred megapascals – easily within the hull’s crush tolerance.’

  ‘I sincerely hope so,’ Kanu said, not for one moment doubting her words.

  She flashed back a quick smile. ‘Well, if I’m wrong – it’ll be quick.’

  Not a stray photon of starlight made it down through the twenty kilometres of icy crust. Fall of Night was swimming now, its motion smoother than when it had been tunnelling. Their angle of descent was shallower and the only sound beyond the ordinary life-support systems was the whirr of water-thrusters. They could have been in the most perfect starless vacuum, adrift between the galaxies.

  ‘Nissa,’ he said. ‘There’s something I need—’

  ‘Can’t you turn off your anxieties, merman, just for a few hours?’

  ‘I don’t think so, no.’

  And there was the first flash of real irritation.

  ‘What’s troubling you now?’

  ‘More than we have time to cover at the moment. This objective of yours – can you tell me a little more about it? I understand you wanting to keep things as close to your chest as possible until we got here, but we’re on Europa now. Shouldn’t I know the full picture?’

  Nissa gave a small sigh and called up a map of the Europan surface, peeled open like an orange. ‘We’re here,’ she said, jabbing with a finger. ‘All these dots, these are abandoned cities. Abandoned doesn’t mean empty, of course.’ Her finger skated to a knot of ruins, settling on one bloated dot. ‘This is Underthrace. It was one of the biggest subsurface settlements before the Fall – a bubble economy, skirting the brink of what was legal or ethical elsewhere in the system. You can see why it would have appealed to your grandmother.’

  ‘You have proof that Sun
day was here?’

  ‘Concrete. I’ve seen the paper trails. When your family’s finances were on the slide, it looks like they tried to move a lot of their more questionable holdings into Underthrace’s independent credit system. My guess is Sunday was shrewd enough to want to safeguard her art as well.’

  Kanu nodded slowly. ‘I’m sure you’re right. It wouldn’t surprise me in the slightest if she banked some of her artworks here. If nothing else, she wouldn’t have wanted the market flooded with her work after her death.’

  ‘I’m glad you approve of my theory. It would be a little disappointing to be wrong.’

  ‘I don’t think you are. But I suspect there might be something else in Underthrace.’

  Nissa twisted to face him again. ‘Something to do with Sunday?’

  ‘I doubt she would have had direct knowledge of it. It’s more likely to have been initiated by the next generation – my mother, her contemporaries. They’d have had the time and the knowledge.’

  ‘The time and the knowledge for what?’

  ‘Nissa, it’s time I spoke frankly. This isn’t what you think it is – there’s something much bigger going on. You’ve come to Europa on some pretext, but so have I – our meeting wasn’t coincidence after all.’

  ‘What do you mean?’

  ‘I always knew you’d be in Lisbon, and that there was a good chance we’d run into each other.’

  ‘No,’ she said flatly. ‘I was there. I saw your reaction. You were as surprised as I was.’

  ‘At the time I believed it was a genuine coincidence.’

  They had descended twenty kilometres since breaking through the ice – deeper than any part of Earth’s seas – and mindless black fathoms lay beneath them still. From the hull there came not a murmur of complaint as it bore the smoothly rising stresses.

  ‘Only yesterday,’ Nissa said, ‘you told me you didn’t feel quite right. I reassured you it was to be expected and dismissed your concerns, but it’s obvious now that I was wrong, for which I apologise. I should have listened to you. But we’re on Europa because I chose to come here, looking for art. Not because of some grand conspiracy you dragged me into. Can you hold on to that simple truth for a few hours?’

  Kanu closed his eyes, opened them again, hoping that the world would have done the decent thing and changed into a less problematic version of itself.

  ‘I want to.’

  ‘So do me a favour and try. There are some floating structures coming up soon which we’ll cut through to save time. We may stir up a few Regals as we pass and I don’t want to be distracted if that happens.’ Then added, under her breath: ‘The four days home are going to be interesting.’

  There was no point in stealth. Fall of Night’s searchlights pushed out at all angles into the surrounding water, turning the little ship into a neon-spined pufferfish. Nissa did not care who knew of her arrival, only that she did not startle the unwary.

  They nosed through looming dark structures still secured to the ocean floor, ovals or spheres for the most part, strung along the tethers like baubles. Each of the ruins was large enough to be considered a city in its own right, and indeed – according to the maps and records – many of them had been autonomous enclaves, bubbles within the bubble, exploring their own fringes of the edge economy.

  Nissa was justifiably nervous. There were hot spots and pressure gradients, evidence of recent or ongoing inhabitation. Kanu felt the tension boiling off her.

  ‘They talk about the Regals as if they’re one thing,’ she said, keeping up a commentary as if it was the only thing holding them both on the right side of sanity. ‘In truth, there are about a hundred different factions down here, and most of them hate each other more than they hate us.’

  ‘Who is your contact? What are you hoping to exchange for the artworks?’

  ‘My contact is the Margrave. As for leverage – money’s useless down here. There are no economic ties to the rest of the system, no way of moving credit in or out.’ But then she noticed something. ‘Oh, what’s this?’

  ‘Show me.’

  ‘Movement. Warm objects.’ She tapped her finger against a smudge of thermal signatures emerging from a fissure in one of the tethered structures.

  The thermal signatures were Regals, but moving too swiftly to be swimming under their own power. There were a dozen of them, organised into an arrowhead squadron. Fall of Night’s sensors picked out the powered drones they were using for propulsion, each Regal drawn along by one of the machines. They could swim, of course – all of the Regals had tails and flippers rather than legs – but machines would always be faster. They were armed and armoured, but it all looked makeshift, cobbled together from technological junk and detritus – the scavenged titbits of what had once been a thriving submarine economy.

  ‘The Margrave’s people?’

  ‘Probably. We’re in his sphere of jurisdiction, more or less.’

  ‘You don’t sound certain.’

  ‘I was told I wouldn’t be contacted until we reached Underthrace itself.’

  ‘Could we outrun them?’

  ‘Oh, easily. Wouldn’t gain us much, though. If you don’t do business with the Regals, you don’t do business with anyone.’

  The Regals carried their own lights. They had glow-sticks and luminous paint, some of which flickered and changed in a way that reminded Kanu of Sunday’s psycho-reactive graffiti. Their submarine armour was horned and bladed. They also carried long, spearlike weapons with triggers and gas canisters.

  Nissa allowed them to approach. She did not increase Fall of Night’s speed or take evasive action. Equally, she did not deviate from their original course.

  The Regals split their formation and surrounded Nissa’s ship. They had no difficulty matching pace. Kanu heard clangs and thumps as they knocked carelessly against the hull, followed by the long fingernail scrape of a spear or harpoon being drawn down the length of the ship.

  ‘It’s intimidation,’ Nissa said. ‘That’s all.’

  A Regal suddenly stationed itself in front of the command-deck window, grappling on with plate-sized suction clamps. Kanu had a much better view of its armour and equipment now. It was a very muscular creature, with a powerful tail and torso, strong-looking arms, wide, webbed hands and barely any neck. It was hard to see its face behind the partial mask covering its nose and mouth, which he guessed was either a breathing apparatus or part of some water-intake and oxygenation system. Its eyes were hidden by strap-on goggles, pushed into the dough of its face like two black eggs. Its visible skin, where the armour did not cover it, was an off-white or pale green.

  The Regal unclipped something from its utility belt that looked like a smaller version of the suction clamps, which it pushed against the glass before fiddling two tubes into holes on either side of its skull. Then it took another item from the belt, a metal cone, and jammed the open end of it hard against the glass. Kanu flinched as the Regal bent its face to the narrow end of the cone.

  Indistinct, watery sounds came through the glass. It was language, possibly even one of the common tongues, but mangled beyond recognition by cultural isolation and the forbidding physics of this environment. Kanu thought he could make out a word or two, in what might have been Swahili – identify, ocean, exclusion, anger – but it was very difficult to be sure. He began to open his mouth, but Nissa raised a cautioning hand.

  ‘They can hear us now, through that stethoscope,’ she said in a low voice. Then, projecting her voice with theatrical clarity: ‘I am Nissa Mbaye. I have come to Europa on peaceful business under a Consolidation permit. The Margrave of Underthrace is expecting me. May I have safe passage?’

  An answer came back. To Kanu’s ears, it was no more comprehensible than the first. But Nissa must have prepared herself for dialogue with the Regals.

  Speaking for Kanu’s ears only, she said, ‘They say the Ma
rgrave won’t speak to me, so I’m wasting my time.’

  ‘That’s a good start.’

  ‘They also say they’re happy for me to waste my time provided I pay a tribute or a toll for passing through this part of the ocean.’

  ‘Were you expecting to pay a toll?’

  ‘I anticipated the demand.’ Nissa shifted her voice into her louder register. ‘I am honoured to offer tribute. I am opening my dorsal cargo hatch. Please take what you will, with my respect and gratitude.’

  She made the hatch spring open. Kanu watched her silently, impressed by her preparedness. The Regal detached its stethoscope and unsuckered itself, then swam around the ship to join its fellows by the cargo hatch. The knocking and scraping had intensified around that area.

  ‘What did you bring?’ Kanu asked.

  ‘Medicines. Vitamins and food supplements.’ But in her voice he heard trepidation. It was all very well speculating on what the Regals would consider an acceptable tribute; it was quite a different matter to put that idea to the test.

  Angry thumps and knocks sounded along the hull.

  ‘Could they damage us?’

  ‘Jam the thrusters and steering gear, maybe. Block the water-cooling intake. Not much else.’

  ‘That already sounds bad enough.’

  Nissa’s expression tightened. The main Regal had returned to the window holding a fistful of small white pills, which were already beginning to dissolve into the water. The Regal mashed the soggy pills and hammered the pulped remains against the glass. It barked some oath into the water, the sound strong enough to reach Kanu even without the speaking cone. Then it gave a jerk of its tail and flicked away into the water.

  The hammering and scraping abated. One or two strikes more, a dismissive final clang, and then they were free of the Regals.

  ‘Did we pass or fail?’

  ‘If we’d failed, we’d know it,’ Nissa said. ‘That was just their way of letting me know they were being generous, that my offering was at the lower threshold of what they consider acceptable.’