Poseidon's Wake

by Alastair Reynolds

‘By which point it’ll be too late to change our minds.’

  ‘I know.’

  ‘And that backwash looks fierce,’ Nissa said. ‘Could easily suck us out again.’

  ‘There is a significant risk of that occurring,’ Swift added.

  ‘Do you have something better to offer?’ Kanu asked.

  ‘Only my very best wishes. I do not think it would help to puppet you – the variables are quite beyond my accounting.’

  Swift was right. Until they were inside a groove, there was no telling how grippy or frictionless the walls were going to be. He hoped they could wedge themselves in tight enough to avoid being pulled back by the drain-off. He hoped there would be room for the Risen.

  But they would not know until they tried.

  ‘We must do what we can,’ Dakota said. ‘We have no love of high places. But to be on the wheel will be better than remaining in these waters. Have strength, Hector.’

  ‘The next groove,’ he said. ‘All of us. Give it everything.’

  They spread out – Kanu, Nissa, Hector and Dakota, with a few metres of clear water between each of them. Kanu reached inside himself for the reserves of energy and concentration he hoped had to be there. Once chance, he told himself – all or nothing.

  The groove began to appear. Centimetres – tens of centimetres already.

  ‘Now!’

  But the others had seen it as well and were not waiting for his word. Nissa spread her arms for one last push against the water – she was a stronger swimmer than he had ever given her credit for. Kanu found his own burst of strength and pushed himself into the widening space. A metre of the groove was now out of the water. He touched the fingers of one hand against the inner surface and jammed his other hand against the cool ceiling. An instant later, he felt the floor press against his feet. He glanced at Nissa. She was in, twisting around to secure herself as best she could. Beyond her, through eyes stinging with seawater, he saw Hector shunt his massive bulk into the same rectangular space. Dakota had to be behind him, but his vision was too blurred to make out more than a suggestion of motion, a confusion of grey mass and surging water.

  Now the lower part of the groove was clearing the sea. He braced against the surge of escaping water, but mercifully it was not as strong as he had feared. And then he was standing, feet on solid ground, hands on the cold interior of the groove.

  Safe.

  ‘Kanu!’

  The lower part of the groove was now fifty centimetres above the water, higher than most of the waves.

  Nissa was moving away from him, towards the Risen. He saw in an instant what was wrong. Hector was safe – he had made it into the groove and was bracing himself in place with his spine against the ceiling. But Dakota was not quite secure. Her head and forequarters were over the groove’s threshold, but the rest of her was still hanging over the edge. There was a metre of vertical distance now from the bottom of the groove to the surface of the water. Her front legs struggled for traction on the slick surface, her trunk stretching into the groove. Hector had turned around to extend his own trunk out to her. Their trunks met, sheathed tips coiling around each other. Had the elephants not been wearing suits, their trunks might have gripped more readily. But the sheathing was too slippery.

  A metre and a half – still rising.

  Nissa squeezed past Hector’s bulk. There was only just room for her to do it without leaning dangerously far out into the void. She reached for Dakota, too, closing a hand around the nearest tusk-like protrusion of her helmet. Kanu in turn reached for Nissa, fearful that she was about to be pulled back into the sea.

  The wheel was still turning. The lowest part of the groove was now two metres out of the water. He could see Dakota’s hindquarters – her legs struggling to find a grip on the smooth surface between the grooves.

  Still the wheel turned.

  ‘Let go!’ he shouted. ‘You’re rising too far! Fall back into the water and try again on the next groove!’

  ‘Help me,’ Dakota said.

  Other than the fading roar of the water sluicing from further down the groove, there was no sound beyond their own breathing, their own grunts and bellows of exertion, their own voices.

  Dakota was completely out of the water now – her whole weight borne by her forequarters. A metre between her tail and the sea. Another metre every three seconds.

  She was starting to slide.

  ‘Hector! You have to let go! Much higher and the fall will kill her!’

  ‘I cannot,’ Hector said.

  Kanu tugged at Nissa, risked a moment of imbalance to free her hand from Dakota’s tusk. But she could only have held on for a second longer in any case, for the tusk was smooth and slick, offering no friction to her palm.

  ‘Dakota,’ Kanu said. ‘Fall. Get into the next groove. We’ll find you. It isn’t over.’

  ‘It is,’ she said.

  ‘No!’ Nissa said.

  ‘Is all forgiven?’ Dakota asked.

  ‘Yes,’ Kanu said, horrified at the growing space beneath her, the drop she was about to take. ‘Yes. All is forgiven. For ever and always. All is always forgiven.’

  ‘Think well of me. Do well by Hector. Think kindly of the Risen.’

  ‘We will.’

  Dakota slipped from the groove. Had Hector not relinquished his hold on her trunk, he would have been pulled over the edge. As it was, the sudden easing of tension sent him falling back into the groove’s depths. Kanu pulled Nissa to him, wrapped his arm around her waist. He dared look down. He watched Dakota fall, tumbling away with her belly to the sky. By then, the next groove must already have emerged from the water. An elephant could never have survived such a fall on Earth. On Poseidon, where the gravity was half as strong again, the impact with the water would be even more severe.

  He leaned into the void, one hand around Nissa, the other gripping the right angle above his head where the top of the groove met the smooth surface of the wheel. He looked for some sign of Dakota, hardly daring to hope that she might have survived. But if her body resurfaced, Kanu was too high up to see it when it did.

  Yes, of course she was forgiven.

  Forgiveness was the least he could offer.

  They were safe, for now – or at least out of the ocean.

  The wheel would keep carrying them higher, and eventually the air would thin and cool. But facing that was better than boiling to death in the ocean, or being eaten by sea-monsters, Kanu told himself, and at least the wheel gave them time and the possibility, however slim, of rescue from above. Dared he pin his hopes on that?

  No – not yet. Focus instead on the present moment, the immediate practicalities of survival. Secure in the groove, there was no chance of their falling out again now. Indeed, as the wheel turned, so the gradually steepening angle of the groove’s floor made it even less likely. Granted, it was a small thing. In an hour they had risen no more than a kilometre, by Kanu’s reckoning.

  He was still breathing the ambient air. It was cooler now – almost pleasant compared to the heat of the ocean’s surface. It would keep cooling as they rose, though, cooling and thinning, and before very long it would not be breathable. They had both needed to tap into suit air and power while swimming, and now – according to the indicator on Kanu’s wrist – he had no more than fifteen hours of life-support remaining. Nissa’s suit was down to a similar margin. Worse than that, some of her suit systems were showing error conditions, presumably because of exposure to the water.

  Nissa was standing at the edge of the groove, a sheer drop beyond her feet.

  ‘We won’t have to freeze or suffocate if we don’t want to. There’s always that.’

  ‘Perhaps we’d have been better off in the ocean,’ Kanu said, fiddling with his suit’s communication settings.

  ‘I’ll regret not knowing more about those moons,’ said Swift,
who was sitting on the very edge of the groove, his stockinged legs dangling over the drop. He had his pince-nez glasses in one hand, squinting against some microscopic blemish on the lens. ‘But I cannot be too ungrateful. To have come this far, to have touched the wheel itself – that’s more than we had any right to expect.’

  ‘We’ve learned nothing,’ Kanu said, overcome by a sudden fatalistic gloom. ‘The wheel’s still a closed book. Just because we’re in it doesn’t mean it’s suddenly revealed its secrets.’

  ‘The grooves are a form of Mandala grammar,’ Swift said. ‘I don’t have to understand it to recognise it. Although a little of the meaning keeps suggesting itself to me rather coyly, but I can’t quite bring it into focus. Do you have the same sense of the numinous?’

  ‘Something came through to us,’ Nissa said. ‘Some knowledge, some information, when we felt the Terror. Just as Chiku told us.’

  ‘Secrets and imponderables.’ Swift settled the pince-nez back into place on the bridge of his nose. ‘I rather feel for Hector. Do you think he will be all right?’

  Hector was balled up at the back of the groove. The Tantor had said nothing since Dakota’s death, and they had been careful not to press him. It was not necessarily some fault of his suit, Kanu decided, but the terrible weight of a loss none of them could begin to appreciate. She had been more than a matriarch to the Risen. She had been the spearhead of a new order of being – a vanguard of promise and power.

  ‘We’re all going to die, Swift,’ Kanu said, allowing a little of his anger to flash through. ‘None of us is going to be “all right”. And you being in our heads isn’t going to change that.’

  ‘You are a rational animal, Kanu,’ Swift said amiably. ‘You would not have placed us in this position unless you thought there was some hope of survival. You know full well that the wheel is turning, and that it will take us higher.’

  ‘Our suits don’t have enough life left in them. It’s just a question of which kills us first – the cold or the thinning air.’

  ‘Or, as Nissa said, you can choose the drop. But you won’t do that. Neither of you has it in you to abandon Hector. For which I am glad.’

  ‘Glad?’ Kanu asked.

  Swift nodded to the sky beyond the groove, where a bright moving spark was crossing the darkening zenith.

  ‘That, if I’m not very much mistaken, is a Chibesa signature.’

  Something crackled across his helmet channel.

  ‘Kanu Akinya,’ he said.

  Another crackle, a silence, then a broken, nervous voice – as if she had not even dared hope she might receive an response and was not quite ready to trust what her ears were telling her.

  ‘This is Goma. Are you all right?’

  ‘For the moment. Ask me again in fifteen hours. Is that your ship we can see?’

  ‘It must be. We can see your thermal signatures on the wheel – we tracked you from the moment you splashed down. The wheel’s bringing you higher – it looks like it’s rotating!’

  ‘Not that it’ll do us much good, I’m afraid, but it felt better than staying in the sea.’

  ‘You’re not out of options just yet, Kanu. You’re coming up to us, and we have every intention of coming down to meet you. Can you hold out for those fifteen hours? You may need every last minute of them.’

  CHAPTER FIFTY-ONE

  Captain Vasin had needed considerable persuasion to take Mposi into the moons’ sphere of influence, still more to contemplate touching down anywhere on the upper surface of the wheel. But even after she agreed to attempt a rescue, her technical objections – fair and reasonable as they were – still applied. Mposi’s design was not compatible with entry into deep atmosphere. The ship would tear itself apart, or roast itself, or both, before it got within thirty kilometres of the surface.

  Eunice argued that they should set down at exactly that threshold, thirty kilometres, while praying that each and every variable happened to line up in their favour. If the hull survived the re-entry forces, and the engine did not quite overheat . . .

  Vasin was having none of that. She would consent to a touchdown at fifty kilometres, halfway to the wheel’s summit on the ascendant side. But she would not let Mposi stay where it landed. They would unload the rescue party, allow them to get to a safe distance, and then Mposi would take off again before the wheel’s rotation carried it over the wheel’s summit and then began to lower it too deeply into the atmosphere on the wheel’s downturn.

  ‘Forty kilometres, if you’re going to make life difficult,’ Eunice said. ‘Then you can stay on station until at least the apex without going too deep into the atmosphere. I like that a lot better than watching you fly off again while we’re still on the wheel.’

  ‘What you like and what you get are two different things.’

  ‘Not in my experience. This is space travel, Captain Vasin. There is no part of it that’s risk-free.’

  ‘Managed risk, then.’

  ‘What do you think I’m doing if not managing your risk? At forty, the ship won’t know the difference from a fifty. We’re looking at a tiny increase in pressure – not enough to hurt us.’

  ‘If I give you forty, you’ll push for thirty.’

  ‘Not this time – I want to live as much as you do. I’d just rather do so knowing we’d done our best for those people.’

  ‘And the elephant.’

  ‘The elephant is one of the people. Speaking of which, we’re going to have to find room for him inside this ship. If emergency adaptations are required, now would be the time to start making them.’

  The sparring went on like that for the better part of an hour, neither of them conceding any significant ground. Goma would have found it infuriating, but the truth was they still had time to make the final decision. Until Mposi was closer to the wheel, their exact point of landing was up for debate. It would only take a few minutes to go shallower or higher, depending on who won.

  Whichever they decided, it was not going to be a simple rescue operation.

  In her conversation with Kanu, she had learned that the three survivors of the Icebreaker expedition who had managed to scramble into the groove were wearing spacesuits. But the humans’ suits would not be able to keep them alive until they were in true vacuum. At best, they had the means to hold out until they were twenty kilometres above the surface, and that would be at the extreme edge of survivability. Mposi’s rescue party had to reach them quickly if they were to make any difference to their chances.

  Eunice had inventoried the supplies. They had plenty of supplementary oxygen and power cells, and the coupling interfaces ought to be common between the various suit designs. But their longest tether was fifty kilometres, and there was no reliable way of coupling the shorter tethers together to make something longer. No matter which way she looked at it, they would have to make do with that one long tether.

  ‘Can we get that down to them?’ Goma asked.

  ‘Yes, I think so,’ Eunice said. ‘Reel out at the maximum speed the winch allows, abseil down the wheel. The wheel’s rotation will tend to act against us, but provided we can move at more than one or two kilometres per hour, we’ll easily beat the rotation.’

  ‘Faster than that, I hope,’ Goma said. ‘And coming back up?’

  ‘Haul in the way we hauled out. And if that fails, we just ride the wheel up to the top.’

  ‘You make it sound easy.’

  ‘I’m involved, so there’s a very good chance it won’t be. Incidentally, what was the part about “we”?’

  ‘It’ll take more than one of us to carry the supplies. Besides, there’s a Tantor down there. Ru and I want to be part of this.’

  ‘Want – or feel you must?’

  ‘Don’t make this harder than it has to be, Eunice. We’re going down, with or without you.’

  ‘And the number of hours you’ve sp
ent in a spacesuit . . . ?’

  ‘We’ll have you along to show us how it’s done, won’t we?’

  ‘I’d argue with you, but I suspect it would feel a bit like arguing with myself.’

  ‘Futile?’

  ‘Boring.’

  Mposi continued its approach to the wheel, moving at much less than orbital speed and slowing all the while. Eunice and Vasin continued their horse-trading over altitude and risk. Gradually Eunice appeared to be getting her message through: given the supplies they had, going deep was the only way of reaching Kanu’s party in time.

  They circled the top of the wheel, recording its grooved structures at maximum resolution in every waveband Mposi was capable of registering. In the hours since Kanu reached the wheel, the sun had set on that part of Poseidon. It was now night-time at the wheel’s base and would remain so for another ten hours. But the wheel’s top was still catching the refracted light of the setting sun, shining a reddening gold. And there were other wheels, and they would all need to be compared, cross-referenced. There was work here for a lifetime – many lifetimes. They had been allowed access to Poseidon for now, permitted to slip through the cordon of moons on this one occasion, but there was no telling how long that licence might be good for.

  Goma figured they had better make the most of it while they had the chance.

  She spoke to Kanu again. ‘How are you holding out?’

  ‘We’re on suit air for fifty per cent of the time. Trying to buy some hours, not that one or two will make much difference. Are you any closer with that rescue plan?’

  ‘Yes, but it’s going to involve you sitting tight a little longer than you might like.’

  She heard the smile in his voice. ‘I’m hardly in a position to complain. What do you have in mind?’

  ‘We’re going to lower a line down to you. But not vertically – it would be too risky to hover Mposi like that, and we wouldn’t be able to offer you any assistance at your end. Better if we lower the ship down the curve of the wheel. We’ll land at the lowest altitude the captain’s happy with – Eunice has talked her down to forty kilometres.’