Poseidon's Wake

by Alastair Reynolds

  ‘Gliese 163,’ he said. ‘That’s the name of the star in the other solar system. We know a little bit about it: Ocular data, a few later observations.’

  ‘No one has mentioned Ocular in a very long time.’

  That was true, but Mposi had not made the reference thoughtlessly. The vast telescope had been Lin Wei’s brainchild, and she had seen it hobbled by Akinya interference. There was danger in bringing that up, he realised. But he was also seeking a direct connection to her past.

  ‘Eunice was your friend, before it all turned bad over Ocular. That’s true, isn’t it?’

  ‘You never knew her. What right have you to speak of her?’

  ‘None, except that I’m her great-great-great-grandson. And I think she may have some connection with the message.’

  Arethusa’s flukes stirred, moving tonnes of water with each stroke. ‘You think?’

  ‘There hasn’t been time for any human ship to get that far out, and send a return transmission. But the Watchkeepers? We don’t know how they move or how fast they can travel. What we do know is that they took three of us with them – the Holy Trinity. Chiku Green, of course. Dakota. And the Eunice construct.’

  ‘The map is not the territory.’

  ‘I understand that the construct isn’t the same thing as your flesh-and-blood friend. But she was getting closer, becoming . . . what’s the word? When a curve meets a line? Asymptotic?’

  ‘Your point, Mposi?’

  ‘Someone has to go out there. We can’t just pretend this message never arrived. Someone went to the trouble to send it. The least we can do is respond.’

  ‘Just like that.’

  ‘We’re getting a ship ready. It’ll make the crossing, with some modifications. Wheels are turning. The expedition will happen – it’s just a question of who goes on it.’

  ‘You have your answer. Send Ndege.’

  ‘That’s the problem. My sister is very old.’

  ‘So are you.’

  ‘But I haven’t been wasting away under house arrest for more than a century. Aside from the political complications, there’s another headache. Ndege has one child, a daughter named Goma. She wishes to take her mother’s place.’

  ‘Either this Goma is very old herself, or Ndege was allowed conjugal visits.’

  ‘Neither. The child was conceived long before Ndege’s incarceration, but Ndege and her husband chose not to have their daughter until later in the colony’s settlement. They kept the fertilised egg in the facility in Guochang – it wasn’t an unusual arrangement in those days. But her husband died, and Ndege pushed herself into her work, and the Mandala event changed everything. For a long while afterwards she could not bring herself to consider the unborn child, but eventually she relented.’

  ‘Did you play some part in that, Mposi?’

  ‘I was concerned for my sister. The arrest was taking its toll on her and I felt that raising a daughter would be good for her soul.’

  ‘Soul. Listen to you.’

  ‘Soul, spirit, state of mind – whichever term you prefer. The point was, Goma gave Ndege something else to think about. The government allowed her to have the child and to raise her while remaining in detention. It was an odd upbringing for Goma, I’ll admit – very cloistered. But it did her no harm, and Ndege is still with us.’

  ‘And now this Goma becomes a thorn in your side.’

  ‘She wasn’t supposed to find out about any of this. But on the face of it, Goma is the better candidate – young and strong enough that there is no question she can endure the skipover interval. It means I won’t be sending Ndege to her almost certain death.’

  ‘Then your conscience can be clear. I do not see the difficulty.’

  ‘Goma’s safety is hardly guaranteed. She might survive the skipover, a hundred and forty years of it, but then what? What will she find around Gliese 163? For all we know it’s a trap of some sort – maybe a fatal one.’

  ‘It sounds like a very long-winded way of killing someone.’

  ‘That’s my hope.’

  ‘Then you must send Goma. She consents, and she is an Akinya. Why do you ask me?’

  ‘I want to know that I am doing the right thing. Regardless of whether I back Ndege or Goma, I’ll still be separating a mother from her daughter.’

  ‘You are an inveterate meddler, Mposi. Always have been, always will be. You Akinyas can never leave well enough alone, none of you. You meddled in Ocular, you meddled in human technological development, you meddled in the fates of elephants, you meddled in first contact, you meddled with Mandala. Is your sister’s happiness really any of your business? You didn’t cause her incarceration – she did, by being rash. And yet you made her bring a daughter into the world because you thought it was what she needed. And now you meddle again – mother, daughter, who shall you send? Whose life shall you cast to the winds?’

  ‘I’m just trying to do the right thing,’ Mposi protested.

  ‘You can’t. It’s not in you. The only thing you Akinyas can be relied on to do is make new mistakes, over and over. The more you try to do right, the worse your choices. You’re a corrupting influence. It’s what the universe made you to be.’

  ‘Is that really what you think of us?’

  ‘Give me a reason to form a different opinion. Give me a reason to think there’s a single one of you who doesn’t have their eye on the main chance. Even you, Mposi.’

  ‘I didn’t ask to be placed in this position. If Goma insists on taking her mother’s place and has a better chance of surviving the trip, who am I to stand in her way?’ But then a sudden, shivering insight overcame him. If Arethusa wished to doubt his good intentions, his hopelessness in the face of an impossible choice, he would give her pause for thought. ‘I’ll go,’ he said, simply and quietly, as if it were the smallest thing.

  ‘In her place?’

  ‘No. I’m not much stronger than Ndege, and besides – I’m not her daughter. But I can be there for her.’

  ‘Brave intentions, Mposi. I know what this world has come to mean to you. But you won’t stand by these words. The moment you’re out of the water, out of my presence, you’ll pretend they were never spoken.’

  ‘I won’t. I’ll talk to the doctors. They’ll find me fit enough. I’m swimming with a sea-monster, aren’t I?’

  ‘Be careful with your words.’

  ‘And you be careful who you doubt, Arethusa. I came to you for your wisdom, not your scorn. You’re wrong about us, especially Goma, and especially me, and I mean every word I just said.’

  ‘Go on, then, Mposi Akinya.’ She uttered his name with sneering condescension. ‘Prove me wrong about you and your kind. I’ll be here, waiting to hear what becomes of you.’

  ‘If you’re still sane by the time we get back, I’ll be glad to tell you. But frankly I have low expectations.’

  He turned from her without another word, thinking of the boat and the dry and distant sanctuary of Guochang.

  Ndege had prepared chai for the two of them. She took a sip, pursed her lips in a habit of familiar distaste. Ndege, who had been born on Zanzibar, maintained that boiled water always tasted wrong on Crucible. Goma had learned to humour her, but the fact was that sooner or later water tasted like water. How long had her mother been on Crucible, that she could not learn to like the taste of it?

  ‘He’s a fool.’

  ‘But a fool with the medical authorisation to do whatever he wants. Anyway, you shouldn’t speak ill of your brother.’

  ‘He’s still a fool.’

  ‘He’s only doing this out of some misguided sense of obligation.’ Goma worked at her own tea. ‘Since I’m going in your place and he can’t do anything about it, he feels he has to be there to take care of me. I can’t blame him for that. He’s wrong, of course – I don’t need him looking over my shoulder – but I can�
��t begrudge him the adventure.’

  ‘No good will come of it.’

  ‘Then you try arguing him out of it.’

  ‘Not much chance of that, Mposi’s like an asteroid – once he’s set on a course, there’s not much to be done.’

  ‘If only we could swap Ru for Mposi, both our problems would be solved. How are things with Ru, by the way?’

  Goma studied her mother’s face, searching for clues as to the intent behind the question. There were lots of new lines lately, complicating the map.

  ‘Nothing’s changed. I’d have told you if something had.’

  ‘But you still speak to each other?’

  ‘We’re colleagues. We work on the same project. It would be difficult not to speak.’

  ‘I mean as wife and wife.’

  ‘What do you want me to say – that it’s all fine between us?’

  ‘It looked like it was, to begin with. You said Ru was accepting of your decision.’

  ‘Maybe she was, at first.’

  ‘So what changed?’

  Goma worked at her chai. She thought, for a second, of finishing it in a gulp and storming out. Her mother had requested – no, demanded – this meeting. It had come at an awkward time and Goma had struggled to alter her plans to accommodate it. She assumed Ndege had something more important on her mind than rubbing salt into recent wounds.

  ‘Ru was just deluding herself, that’s all. Can we talk about something else?’

  ‘I’d rather we talked about Ru.’

  Recognising that she was now too deep into the conversation to back out gracefully, Goma said, ‘When there was a chance of the expedition losing approval, Ru thought she could talk me out of it gradually, or trusted I’d eventually lose my nerve. But it’s going ahead, and I haven’t changed my mind.’

  ‘It’s my fault – I should have been more steadfast, refused to let you and Mposi talk me out of the expedition.’

  ‘None of it’s your fault. It was always a bad idea, you going. I’m your daughter – why shouldn’t I stand up in your place? I’ve even had the medical examination – I’m as fit as any skipover subject. You’d never have passed the first test. When you failed – as you would have – we’d be exactly where we are now, with me going in your place.’

  ‘I just wish something would persuade her.’

  ‘It doesn’t matter what Ru decides now. You know how sick she’s made herself. Her nervous system’s a wreck – she neglected the medicines for too long, and now it’s a case of patching up the damage. She hasn’t been formally tested, but my guess is she wouldn’t obtain skipover consent. It’ll be hard enough for Mposi.’

  ‘Chiku and Noah put us through skipover many times aboard Zanzibar,’ Ndege said. ‘It was hard. I won’t lie. Like dying back into life every single time. You never get used to it. But it would still be good if you and Ru came to some understanding, so that you could at least be friends again. I can’t bear the thought of you parting with this distance between you.’

  ‘I don’t think there’s anything to be done about Ru, any more than you can turn Mposi around.’

  ‘I hope things aren’t that desperate for either of us.’

  ‘I can’t speak for you and Mposi, but Ru and I are past any point of reconciliation. We’ve said everything, had every argument. There’s nothing left for either of us. Sooner or later – certainly before I leave – we’re going to have to talk about formalising our separation.’

  Ndege looked stunned, as if she had never foreseen this development.

  ‘Divorce?’

  ‘Kinder on both of us,’ Goma answered, with an easy-going shrug that still left her ripped inside. ‘Ru can get on with her life back on Crucible. One day she might even be able to forgive me.’

  ‘There’s nothing to forgive.’

  ‘You would say that.’

  ‘You’re my daughter, and I’m allowed to think the best of you. You’ll always be in my thoughts, Goma, even when the ship’s left – even when you’re too far away for communication.’

  ‘I don’t want to think about that day.’

  ‘That’s not going to keep it from happening.’ Ndege let out a sigh. ‘With that in mind, there’s something else I want to talk to you about.’

  ‘Something besides Ru?’

  ‘Yes, and I wish you weren’t so glad of the fact.’ Without warning, Ndege scraped back her chair, rose from the table and moved to one of the bookcases. ‘It’s a delicate thing and it could get both of us in trouble, so you’d best keep it from my brother for now. Did I ever speak to you about Travertine?’

  Goma nodded vaguely. ‘Some old friend of yours.’

  ‘Much more than that. A staunch ally to my mother, on the holoship. Then a loyal friend to me, after your father died and the world decided I needed burning. Other than Mposi, Travertine was one of the few people who’d still give me the time of day. I could never pay ver back for the love and loyalty ve showed me.’

  Goma had seen public images of Travertine in the government halls of Namboze and Guochang. Peevish and stern, severe of countenance, it was hard to square the face she remembered from those pictures with warmth and companionship.

  ‘What has Travertine got to do with any of this?’

  ‘Ve shared my interest in Mandala – it was a scientific puzzle, after all. Catnip to Travertine. Ve helped me design the communications protocol – the shades and illuminators we used to project light and darkness onto the walls. We cobbled them together with solar panels, mirrors, dome material, sheets of agricultural membrane – anything we could get our hands on and rig into place quickly. All very crude, but it worked.’

  Goma managed a smile at her mother’s customary understatement.

  ‘After the event,’ Ndege went on, ‘I did my best to obscure Travertine’s involvement. Ve already had a stain on ver character from the Zanzibar days – this would have been too much. I took more than my share of the responsibility, but since I was going down anyway it was a small price to pay. Regardless, Travertine remained my friend and never allowed me to forget ver gratitude. That is why ve gave me the list.’

  ‘What list?’

  Ndege’s fingers hovered over a row of books, finally settling on a slim, dusty-looking volume. She brought it to the table, holding it upright between both hands, like a shield.

  ‘Gulliver’s Travels,’ Ndege said. ‘Have you read it?’

  ‘No.’

  ‘Good – I wouldn’t recommend it.’ Ndege sat down again, then opened the book and paged through it until a slip of paper fell out onto the table. Goma saw a list of handwritten names running down one column, and numbers in the other.

  ‘What are those?’

  Ndege coughed to clear her throat, touching a hand to her windpipe. ‘After the Mandala event – after my crime – a great deal of attention was paid to the destruction of Zanzibar.’

  ‘There would be.’

  ‘Well, yes. It was clear that I had triggered some sort of response from Mandala. The public focus was on the obvious – the destruction of Zanzibar. But Travertine dared to look beyond the obvious – dared to ask verself a different question. What was Mandala pointed at when the event happened?’

  ‘The sky.’

  Ndege smiled patiently, well used to Goma’s sarcasm by now. ‘Beyond that. Crucible itself rotates, and revolves around its star. Mandala’s gaze sweeps the heavens like a lighthouse beam. At the precise time of the event, Mandala was directed towards a specific patch of the sky. That region happened to include Gliese 163.’

  This was news to Goma – she had heard no mention of this association from anyone else – but she was careful not to accept the information without question.

  ‘You haven’t said how big the patch of space was, or how many other stars were in it.’

  ‘You’re right to
be suspicious of coincidences. Then again, you’re a scientist too, so I shouldn’t be surprised.’ Ndege’s fingers tapped the paper. ‘But so was Travertine, and ver methods were rigorous. That’s the point of this list. Travertine identified a few hundred candidate stars in the direction of Mandala’s gaze. They were all at different distances, of course – some of them hundreds, thousands of light-years away. Travertine ignored all of those. Ver only interest was in the nearest stars – those from which we might expect to receive a return signal.’

  ‘A return signal?’

  ‘What if Zanzibar got in the way of something? An energy pulse, yes – but not something meant to be destructive. Something meant to cross interstellar space from one solar system to another? Travertine’s next question was: when might we expect a response? These are the numbers – the dates.’ Ndege’s finger moved down the list to the entry for Gliese 163, her too-long fingernail scratching against the paper. ‘Do you see the significance? My crime happened in 2460, so the earliest response from that system couldn’t arrive until one hundred and forty years later. That’s 2600.’

  ‘Twelve years ago.’

  ‘Long before Mposi came to me about his signal – agreed. But close enough to Travertine’s prediction to raise goosebumps. And you see how ve underlined this star in particular? Out of all the candidates, Gliese 163 was the nearest, the most likely to have habitable worlds. Travertine always suspected it was the target of the Mandala signal.’

  Goma was silent. There was a possibility, she supposed, that the list of stars and dates was a hoax, recently engineered by her mother. But Ndege had no history of that sort of fabrication. More than that, a hoax would serve no obvious purpose, benefiting neither of them.

  ‘I don’t know what to make of this.’

  ‘Someone sent us a signal, Goma. It was a human message. Personal. It said “Send Ndege”. Someone knew my name. How could that have happened if there were no people in the Gliese 163 system? And how could people have got there, if not aboard Zanzibar?’

  ‘Zanzibar was destroyed!’

  ‘Some of it, maybe, but not necessarily all of it. How much rubble is in the ring system, anyway? Travertine didn’t think the mass added up. Ve believed there was a significant discrepancy – that a huge chunk of Zanzibar was never accounted for. Of course, no one else gave a damn.’