‘It might not sound much, but much more of Earth’s water, for example, will start evaporating, will linger in the air rather than fall back as rain – and we’ll get even more heating from that, by the way; water in the air acts a greenhouse gas.

  ‘Meanwhile the carbon dioxide cycle will start breaking down. The overheated, exposed rocks will weather, cracking, reacting with the carbon dioxide in the air, drawing it down … You might think less carbon dioxide is good, because less warming. Yes, but vegetation needs carbon dioxide to survive. The most advanced photosynthesising plants will wither first, without the cee oh two from which they extract carbon to build trunks and leaves. The herbaceous plants, deciduous trees, evergreen broad-leaf trees, even some conifers – most of our crop plants too – all gone.’

  ‘All this after the first century?’

  ‘All this after the first century. In the decades after that, extinctions on a massive scale will follow – whole domains of life. Photosynthesis itself will eventually collapse. You might still get a few termites and such around the hydrothermal vents at the bottom of the oceans.

  ‘But by two hundred years there will be a final “runaway greenhouse”, as they call it, as all the water evaporates. The oceans gone. And life will dwindle further, until—’

  ‘I think that’s enough. Thank you. All this if we stay in that damn quasar beam, and if it keeps strengthening as it has so far …’

  ‘That was a tough listen, Madam President. I suspect it’s going to be a lot more complicated than that, in good and bad ways. Earth’s systems have a lot of inertia, and a lot of complexity … But in essence, similar projections we made a decade ago haven’t changed.’

  Mason shrugged. ‘But in a way the details don’t matter. For sure it’s going to be a tough tag-line when I run for re-election.’

  If that was a joke, Salma thought, nobody was laughing.

  Doria Bohm was exploring her own tablet. ‘And don’t forget the rest of us. Earth, with the richest biosphere, may be the most vulnerable and will suffer the most – but the other worlds will be damaged too. We on the Moon might survive in deep lunar caves with ultra-strict recycling. Any life on Mars we haven’t yet managed to destroy will be lost when the deep, ancient aquifers finally burst and dry. The ice giants will melt. Oh, I just found an estimate: Ceres will be melting after about twelve thousand years—’

  ‘The comets,’ Hild said. ‘In the Oort cloud. We will surely lose those quickly, given how disrupted each can be by the heat of a single passage past the Sun, lasting a few months of close approach …’

  Salma had more or less followed these arguments, had heard some of it before over the years. But now, hearing it all set out so forcefully, so clearly, she felt overwhelmed. Was she going to live to see the end of the world – of all the solar worlds?

  She curled over herself, knees tucked up against her chest, arms beside her head, a childish pose she should long have grown out of.

  Hesitantly at first, Feathers put her long, fragile arms around her friend’s shoulders, and hugged. Salma could smell her, the wood-burn tang of the feathers, heard their soft rustling.

  Salma hugged back. ‘I love you,’ she murmured.

  And Melanie Mason held up an unreal hand.

  The chattering, the morbid speculation, stopped.

  Everybody came to order.

  ‘Thank you,’ Mason said now. ‘I’ve pushed you a long way here, into speculating about stuff you really don’t know much about. I know scientists don’t like to do that, and I appreciate it. This has been hugely useful – even if, I suspect, my principal will want to run it all through a dozen think-tanks to confirm it. But we are emphatic that none of this is in any sense your fault. You of the Shadow. There was a button to be pushed here; whoever got here first would have pushed the damn thing.

  ‘But – I know the President is going to ask, because I would ask – what the hell are we going to do about this now? Or, more to the point, what are you going to do? Because you are the ones on the spot.’

  ‘Nothing more without authorisation,’ Hild said, looking around the group. ‘I mean, from everybody. From all our – nations. Earth, Moon, Conservers. This is too big for our petty factionalism. Agreed?

  ‘But as to what we could actually do now, given authorisation – the next step seems obvious. We try sending the new Hawking signal, to this world. On behalf of mankind. One step up from the simple echo we sent before. Maybe, if they know we’re here, we’ll be spared … Or not. Anyhow we deal with whatever follows. We, the crew.’ She glanced around once again. ‘If this audience is done let’s start planning. And send that signal, since it’s all we’ve got.’

  Melanie Mason nodded. ‘Wait for my authorisation – my principal’s, once she’s absorbed all this … That’s going to take days, of course. Lightspeed. And I should consult the Conserver councils, the Moon. But I think you could get on with your preparation for now. And then – well, we do what we can. Thank you again. Let’s hope we can make sense of all this.’

  Caspar grinned. ‘And save the Solar System?’

  ‘Ideally.’ And the President of Earth winked out of existence.

  32

  Once the decision was made to perform the second Hawking experiment, Planet Nine was hastily evacuated.

  The experiment was still under the control of the Shadow crew, but now the Cronus people were officially in charge of the situation. And Elizabeth Vasta’s immediate recommendation decision was to evacuate Feathers from the faux planet. It would be the first time she’d been taken away from Nine since her first discovery and retrieval.

  Salma, feeling somewhat excluded, tried to follow the logic of that. Vasta, with surprising patience for someone so high up in Earth’s government, took Salma aside and talked her through it.

  ‘I know you’ve lived here for eleven years, Salma. Much of your own life. You’ve done well to survive here, and to have explored the situation, all of you – and you, especially, Salma, have been crucial in supporting the asset.’

  And that was a slip, Salma knew. The asset. A jargon term the Earth-based folk used for Feathers. Frowned on by all the Shadow crew.

  ‘And I imagine it feels like home to you,’ Vasta said.

  ‘It is home. And it’s certainly Feathers’ home.’

  ‘OK. But this is also a scientific experiment – probably of strategic, even existential importance for all of us. We have to control it scientifically, and have regard for safety.

  ‘The last time the Hawking experiment was run, this whole object – artefact, natural phenomenon, Planet Nine – unfolded, didn’t it? From a compact little ball to a planet-sized sphere. We don’t know how that happened. We do know it’s not some kind of miracle, as it followed scientific law, to some extent – the mass was conserved, gravity still worked as it should. But we have no way of predicting what might happen when we try again. Just as we never would have guessed what followed before – Feathers, and the quasar, a triggering that had to have happened in the deep past.

  ‘But the best thing we can do is repeat the conditions we, or rather you, applied at that first experiment. You stood off from the black hole, in space, reflected the Hawking signal back – and then ran as the object expanded. So that’s what we’re going to try now. Use the same conditions, see what happens next. I mean, nothing might happen – nothing that’s observable to us, anyhow. Or something as extraordinary as the last transformation. We just don’t know. So we’re being cautious, taking it step by step. As before we’ll stand off while it all unfolds …’

  Salma had no say, of course, in whether all this was to be done, and how. It was polite, and kind, of Vasta to try to explain the logic to her at all.

  She still had the feeling that it was wrong to keep Feathers away from Nine, whatever they did.

  She spoke to her friends from the Shadow, and they were sympathetic, but she got a lot of shrugged shoulders.

  ‘We just don’t know what’s right or wrong to do here,’ Meriel said. ‘As we haven’t from the start of this – adventure. We’ve always just had to feel our way in, step by step.’

  ‘But now these people from Earth have ignored all that and are just taking over.’

  ‘Well, that’s government for you. And Elizabeth Vasta, for one, is much better qualified to make crucial decisions about this than you or me, kid.’

  ‘But she hasn’t been here. And she’s not a cosmologist, or a biologist, or … She’s a climatologist!’

  Meriel had to smile. ‘Like every planetary president’s top adviser has had to be for a century. We’ll just have to trust her to make the right decisions.’

  Salma didn’t, though. She didn’t see how anybody, any person, could make the right decisions here, it was all so abstract, so huge. And certainly not a politician so remote she couldn’t even speak to them in real time. She thought they should follow the crew’s own instinct – the crew who had lived with all this for so long.

  But she had no say in the matter. And nor, of course, did Feathers. And as crew from the Cronus helped the Conservers of Shadow collapse their big old collection of habitats and pack everything away, Salma could only stand by with Feathers, and watch, and try to stay calm.

  Feathers was quiet, even sullen.

  This is wrong, Salma thought. Feathers knows it, somehow. I feel it.

  That feeling became stronger after the evacuation, and Nine had been left uninhabited.

  Feathers didn’t take to the strange environment of the Cronus. Once aboard, she had quickly found a corner in a disused hold where she could establish her nests of cloth and other junk – stuff donated from the Cronus crew and passengers under Meriel’s guidance. Over the first twenty-four hours, Salma spent as much time as she could with her there.

  And then a first attempt was made to ‘light up Planet Nine with more Hawking scribble’, as Boyd Hart put it. To repeat the first run as closely as possible, the signal was to come from the Shadow as before, with the set-up assisted by crew from the Cronus, hand-picked by Caspar himself, and much more extensive science observation run from the larger ship. But Nine was evacuated of crew.

  Salma for one was dubious. It seemed obvious to her that the first signal had evoked a human-friendly response – at least, the gravity had been acceptable for humans – and the presence of Feathers seemed nothing but a signal pointed straight at the human visitors. There was more debate about the evacuation. The idea of having humans down there now was pushed by Hild and Meriel, in the end vetoed by Elizabeth Vasta and Caspar.

  So the Hawking signal was fired back just as in the first experiment …

  But this time nothing came back from the signal itself, save faint reflections from the surface of the object. This time there were no changes in the basic configuration – the mass, the gravitational properties. No dramatic unfoldings of Planet 9 as before – or collapsing, come to that.

  They let some time pass, in case of some delayed response.

  When there was no response, they tried again. A second failure.

  After that, Meriel spoke to Vasta, Caspar and the others.

  With quiet insistence she said, ‘Maybe we should follow Salma’s instinct after all. And the rest of us from Shadow, frankly. Maybe Nine needs inhabitants, some of us, to make the next step work – in particular Feathers, whatever that step might be. After all, Feathers came safely through the first transition—’

  ‘Barely alive,’ Vasta pointed out. She shook her head. ‘But what we’re doing isn’t working. We may as well try something else. A landing party, at least, though, like before. It doesn’t seem right to send Feathers down alone … Even if your interpretation has always been that Feathers herself was essentially a message aimed at us …’

  They left it for twenty-four hours before trying again – just in case there was some delayed reaction to their earlier attempt. Then, what Vasta called a ‘landing party’ was quickly assembled, briefed, and suited up.

  The party of just two, as initially defined, was to consist of Elizabeth Vasta of Earth, and Doria Bohm, representative of the Lunar Consortium. Doria, a skilled pilot, could fly a shuttle down.

  But none of the Shadow crew were to be sent down – and not Feathers.

  Boyd Hart, the oldest crew member of the Shadow, claimed not to be surprised. ‘It’s all politics. Leaving behind the crew who have been here for years in favour of representatives of the two big power blocs, Earth and Moon, ha! What are they going to do, negotiate treaties?’

  Salma, too, felt this was all wrong, but on a more visceral level. She was especially surprised at the exclusion of Hild, and she went and told her commander so.

  Hild was philosophical. ‘Well, that’s a point. But I’m not going to protest. If this fails there will have to be other attempts. Things have a way of working out. You just have to be patient, Salma …’

  Salma gave up. She did accept that, having grown up on the Shadow among its small crew, she knew too little about people en masse. She knew something about personal relationships, a little about feelings, but nothing much about politics. She didn’t have the tools to argue the case.

  And Hild was proved right, when the first signal attempt was made the following day.

  Vasta and Bohm descended, crammed into a rattly Cronus shuttle. On landing they stood proud, side by side, in their pressure suits, with equipment sacks on their backs, and camera drones fixed to their helmets.

  Salma thought they looked pretty silly when the Hawking signal splashed over them and Planet Nine remained stubbornly inert. And sillier still when they had to crawl back into the lander and scuttle home to Cronus.

  It was on the day after that, in one of the grand lounges aboard the Cronus, that Hild called a meeting, and, in her soft, persuasive way, made a fresh case for a different landing party – finally including Feathers.

  ‘Feathers came out of the first experiment, after all,’ she told Vasta. ‘You know we believe she is a kind of embodiment of whatever message we are being sent – part of it, at least. I know that you might think her presence would inject too much randomness into this, a lack of control. But maybe she is some kind of – key – to what follows now. Maybe we simply have to demonstrate we’ve been able to care for her – at least tolerate her. Who knows?’

  A bit theatrically, Salma thought, Hild glanced around at the gathered group, especially the Cronus folk, as if daring them to contradict her.

  But Vasta just shrugged, rather than argue back. ‘On reflection I think you’re right. And, further, we ought to have been listening to what you Shadow folk have been trying to tell us all along. You’ve been on the spot. You’ve made the right guesses, figured out the right logic, to get us this far at least. And yes, you’ve made such a good connection with Feathers.’ She seemed to think about it for five more seconds. Then she said, ‘So let’s do it. We take Feathers down.’

  Salma clenched a fist. ‘Yes.’ It came out as a hiss – she’d used the exaggerated way she spoke the word, along with the gesture, that she used for Feathers. And, she saw, looking over, Feathers understood. A rustle of wing feathers.

  In the discussion that followed, the rest of the new landing party quickly self-assembled, with some quick decisions by Vasta, Hild, Caspar.

  ‘OK,’ Vasta said at last, a monitor in her hand. ‘So Doria Bohm is going to pilot the shuttle. As before. Otherwise, I will be going along. And, we agree, we must take the creature called Feathers.’

  Just Feathers, Salma thought, seething inwardly. The person called Feathers would do …

  ‘And if we take Feathers, we have to take Meriel, who’s cared for her physical and medical needs since she was found.

  ‘And Salma, who similarly has been a constant companion.’

  And that was a shock to Salma.

  Her first reaction was jubilation. Her second, a stab of terror. Do I really want to walk through that doorway again? Even if I’ll be part of a team. Myself, Doria, Vasta, Meriel …

  But Salma had an odd, unidentifiable feeling as she thought this through that this latest selection was the right one, regardless of discussions of skills and experience. It felt right to her, this particular group. A piece of the puzzle that slotted home, though she didn’t understand how.

  Half-consciously she fingered the pendant on her neck.

  And the strange but familiar hand of Feathers slipped over hers, and squeezed.

  It took six more hours for the revised preparations to be made.

  Then another six hours for rest, mandated by Meriel for herself and the others, an injunction backed up by the medical team on Cronus.

  Then they finally suited up. Feathers wore the clumsy environment suit, with its repairs and adjustments, that she had worn every time she had left the surface habitats since the Shadow crew had first discovered her.

  And then, at last, the five of them crowded into that small shuttle, mated to the hull of the Cronus.

  The passengers took their seats. From where she was sitting, Salma could see the back of Doria’s head, sitting up in the pilot’s position, hear her low voice as she swapped checkpoint markers with the Cronus crew.

  At last the shuttle cast off from the liner.

  Looking back, Salma could see the huge curved forward hull of the Cronus, that long spine, receding, slowly, slowly. The relative movements were silent, at first imperceptible – but acceleration smoothly mounted, pushing them back into their couches.

  Doria, a little fussily, made the rounds of the passengers now, using handholds to brace against the acceleration, checking their seat harnesses.

  And she repeated their planned itinerary. ‘Remember the flight profile. We’re decelerating from orbit around Nine. We’ll get up to about a quarter Earth’s gravity. That won’t last long. Then we’ll have a sterner bout of deceleration to lower us down to the surface – no air for aerobraking here, remember, you Earth folk. No gliding down. This will be more like landing on the airless Moon – my Moon. Earth’s moon. Landing on rockets. We should be settling on the ground, at the site of the old habitat, in a couple of hours …’