Terminus said, You have been confronted with the existence of the creature you call Feathers.

  ‘Yes,’ Meriel said. ‘Yes! Which was some kind of proof of all that. So we were on the right track, weren’t we? We talked about this, Salma. Your little friend … Remember how we speculated about how unlikely it was that two planets could produce humanoid-shaped species, as similar as, well, you and Feathers? How our universe isn’t big enough, or old enough, to have done that with any reasonable probability? So she had to have come from someplace else. Some universe elsewhere. Bigger, or older, than ours – or both maybe.’

  Vasta said, ‘And now, standing here, you don’t need an exercise in probabilistic mathematics to get the idea. Look around you. This planet, too old for our universe, remember?’ She gestured at the sky. ‘And that galaxy core up there – that’s too young, right? There hasn’t been a feature like that in our universe since it was half a billion years old. Compared to thirteen billion years today.’

  You are correct. This place is artificial. It has been assembled as an intersection of three time zones: your own epoch, the very early days of your cosmos—

  ‘This active galaxy core,’ Vasta said.

  And its very late days.

  ‘Yes, yes. This ancient, dead planet, brought from the far future.’ She glared at Terminus. ‘I don’t know whether all this gaudy display is meant to uplift us, or crush us into some kind of submission.’

  Neither, said Terminus calmly. I have come here, I show you this, to save you.

  Vasta glared at it. ‘To save us from what?’

  From the inevitable extinction of your own universe, and all life within it.

  35

  There was a long pause.

  ‘Well, that’s a downer,’ Elizabeth Vasta said. ‘As the nearest to a government representative standing here, I officially have no idea how to respond to that.’

  Meriel snorted. ‘How about, thanks?’

  Salma, thinking over all this, raised one hand – the other gripping Feathers’ hand tightly. ‘Terminus. I have a question.’

  Ask it.

  She flinched back at those words, coming as they did from a floating sphere. It’s just some dumb machine … She lost her nerve. She looked around at the others. ‘I don’t know if I should say anything. I have no, umm, authority here. Is that the right word?’

  Meriel, standing next to her, rubbed her back through her suit. ‘You’re the one who made first contact with the alien, kid. You have the authority.’ She glanced over at Vasta, who nodded. ‘Ask your question.’

  Salma faced Terminus again. ‘If you’re so powerful – if you can cross universes – why are you even talking to us? Why don’t you just – save us? Or destroy us? Or whatever it is you intend to do?’

  Doria laughed softly. ‘Good question, kid. And maybe one the rest of us are too arrogant to have considered.’ She faced Terminus. ‘She has a point, doesn’t she?’

  Indeed. In a sense it has already been necessary for you to save yourselves. By getting this far.

  That caused a pause. Salma was aware of glances from the others. But she had more questions.

  ‘Have you saved others, before? Or helped them save themselves? Others like us?’

  Yes.

  ‘And are there others like you?’

  Like me. Yes.

  Vasta frowned. ‘Like you?’

  With similar origins.

  Vasta frowned. ‘What origins?’

  Disparate. Isolated.

  The multiverse is a very large place, growing continually and eternally, and it is almost totally devoid of life and mind. Almost, but not entirely. Life forms like yours – embedded in the physics of a given reality – can emerge from that reality. Spontaneously. It is rare, but it happens.

  And, we concluded, we who owed our own lives to still more unlikely accidents, there is nothing more precious than life and mind. It is to be found, cherished, protected – encouraged to grow.

  Vasta said, ‘So what does that have to do with planting humanoids in our Solar System, and a quasar in our galaxy?’

  Terminus replied bluntly.

  You are alone in your universe. A potentially life-filled universe.

  Only you.

  Your universe is young.

  That there should be living things, arising from Earth, based on carbon and water, arising spontaneously – by chance, by random combinations, as it happened – is extremely unlikely. The probability that you exist at all, in such a young universe, is so nearly zero that it is all but inevitable you find yourselves alone.

  In that, your birth was like my own. Highly unlikely.

  Salma looked around, to see how the others were taking these extraordinary revelations.

  Alone …

  Meriel looked – disappointed. Doria bewildered, perhaps.

  But Vasta seemed determined to pursue this logic. ‘OK. Alone. Because either we are alone, the only sentients in the universe, or isolated – life and mind is so scarce we wouldn’t have the time to find the alien before the stars went out. Or maybe not even the time for another instance of spontaneous life creation.’

  Terminus seemed to hesitate. Then: You are correct.

  ‘In that case,’ Vasta went on grimly, ‘we have a duty – well, not to go extinct, at least.’ She smiled. ‘Wow. You Conservers were right. We ought to survive as long as we can, if the universe is part of an infinite and eternal multiverse, much of it devoid of life … And I find myself in sympathy with a godlike being from a higher reality. Who’d have thought it?’

  The others managed to laugh.

  But Salma found she dared to speak again, to challenge.

  ‘So, Terminus. How does this justify dumping a sentient being into another universe? Not to mention creating a quasar in our galaxy? And …’ She lost her nerve.

  The others glanced at her, and Vasta nodded. Go ahead.

  She took a breath. ‘Feathers here. Alone, terrified … You used her as a sort of teaching aid, didn’t you? So we could figure out the context, the likelihood that she must have come from some other universe entirely. But if we hadn’t found her, or if we hadn’t been able to help her survive—’

  It was a matter of means.

  Of available tools, if you like.

  The delivery of Feathers as, yes, an aid to understanding, was a by-product of the establishment of the bridge in the first place.

  Vasta snapped, ‘What bridge?’

  You understand that a bridge must be made, built, between one universe and another. I needed such a bridge to reach you. But such a bridge cannot be built from one side only.

  ‘OK,’ Vasta said. ‘If you want to build a bridge over a river, you have to start from both banks and meet in the middle.’

  Doria murmured, ‘Only somebody who grew up on Earth itself would get that metaphor.’

  We could only reach out. We gave you Feathers. It was up to you to reach back. Or not.

  ‘Ha!’ Meriel’s laugh was bitter. ‘So it’s our fault, even though we couldn’t possibly have guessed the consequences of playing around with Planet Nine. But we went ahead anyhow. We can blame nobody but our own hubristic, meddling, impetuous selves. Without that we wouldn’t be tangled up in all this, whatever it is—’

  You would not have had the gift of eternity, Terminus said evenly. Or the promise of it.

  Salma said, ‘But it could only be us, because we are alone. We humans. He said so. We are the only ones he could – use. So how did you find us in the first place, then?’

  The bridging technology is very old, and very smart.

  That was all it would say.

  ‘I doubt we could understand,’ Vasta said, her voice colder still. ‘Not yet, anyhow. Very well. And what of our galaxy? As Salma asked, has it been necessary to bathe planet Earth in quasar light in the process of creating your bridge?’

  The disturbance is temporary. Yes, it was necessary to establish a high-energy link between your galaxy core and your home world. Energy to enable the next steps in the process. We needed your help to establish the bridge. It could only be humanity, for there is only humanity in your beautiful but barren universe. But you need not have chosen to participate.

  Vasta looked angry now. ‘We didn’t know what we were meddling with!’

  Then, Terminus said, you might have been wiser not to meddle at all.

  Vasta glared, but evidently had to laugh. ‘To be fair, that’s pretty much what I tell my students all the time. Good take-home lesson—’

  ‘But we did meddle,’ Salma said. ‘We did open your box. So what now?’

  Now, Terminus said, we offer you eternity and infinity. We save you from this.

  And the sky went pitch dark.

  36

  Salma felt Feathers cling closer, heard a low, caw-like moan.

  After only a few seconds, their smart suit lamps lit up. They stood in their isolated splashes of light, hopelessly dim compared to the lost galaxy-birth glare.

  Glancing around, Salma saw that nobody was moving, not at first. That was a drill she had learned during the long years on the Shadow: if the power failed, if the lights went out, you just stayed still, until you were sure you weren’t going to collide with something, or suffer some other harm – or, worse, cause harm to the ship.

  Terminus was just hanging in the not-air, its curves rendered visible, just, by the suit lights.

  When the light didn’t come back, Doria murmured, ‘Come to me. All of you. Best we stay close.’

  They moved in cautiously, avoiding any stray bits of kit on the ground. They came close enough to touch each other. As Salma hung on to a very quiet Feathers, Meriel rubbed Salma’s own back. All of which Salma found hugely reassuring.

  ‘So,’ Vasta said, her voice admirably steady, ‘did the stars just go out? The active galaxy you showed us—’

  All the stars have gone out by now, Terminus said. We are now in the very far future.

  ‘Nice display,’ Doria said. ‘Like a planetarium I once visited—’

  This is the far future of the same cosmos. The active young galaxy I showed you has long since darkened, dispersed, even its dead stars evaporating from its gravity well. The planet you stand on was already old, as you know.

  Vasta said, ‘Feathers’ planet.’

  Now it is far older still. It still exists, in fact, only because it has been consciously preserved. For your convenience.

  ‘Thanks,’ Vasta said ironically.

  You measure time in years. Very well. When you, these individuals, were born, your universe was thirteen billion years old. Your world was warm, active, illuminated by your star, and heated from within by its own store of residual formation heat, by radioactivity.

  After ten billion more years your star will be a white dwarf, quietly fusing its remnant hydrogen and helium, yielding little heat. After a hundred billion years, its Sun long exhausted, your Earth will be cold, inert, like this planet.

  After a thousand billion years star formation will stop, across the universe, the raw material exhausted. A hundred times longer again, and the last stars will die. Soon even the star-corpse remnants will evaporate from the Galaxy – escape from its gravity well through chance collisions and encounters.

  Vasta grunted. ‘Like gas molecules crowding out of an open jar.’

  The universe will be populated only by supermassive black holes and stellar remnants, the cold corpses of the stars in evaporating galaxies – and cold, inert planets like this one. But in the still longer term matter itself breaks down—

  ‘Proton decay,’ Vasta said. ‘Such a slow effect we aren’t even sure it exists. Matter itself falling apart, after – what, a trillion trillion trillion years? And beyond that—’

  Beyond that even the most massive black holes will evaporate.

  ‘Hawking radiation,’ Salma guessed.

  Meriel rubbed her back again, through her pressure suit, a distant sensation.

  There will then be nothing but a thin mist, the relic of the decay of matter itself, in an endlessly expanding spacetime.

  Vasta said, ‘They used to call it the heat death. From the Big Bang, through a few trillion years of light and life and hope, and then just endless expansion—’

  You are not alone. We have contacted many others of your kind – I mean, the products of young universes. And we have found a way to save you.

  Save you from the heat death of your universe.

  Save you from an epoch like that of my own cold birth.

  This is my promise to you …

  Terminus fell silent. It just hung there, bathed in their suit lights.

  And the sky exploded.

  37

  That was what it felt like.

  Feathers squealed, and cowered away from the light.

  Salma instinctively grabbed her, put her gloved hand at the back of Feathers’ head, and pressed her face against her shoulder. And she jammed shut her own eyes.

  Meriel called, ‘Check that your visor filters are working. Resetting all of your suits remotely. Salma, check Feathers—’

  ‘I’m on it.’ Salma knew the drill; they had practised for such contingencies often enough. She tapped her own visor to ensure opacity, then opened her eyes cautiously. With the helmet closed, she saw only interior displays. She felt for the test panel on her own chest and tapped it. A display at the base of her field of view showed a mix of amber and green, the amber lights flicking over to green, one by one.

  She was still holding Feathers, and when she touched Feathers’ visor with one gloved finger she got a similar display, though the switch to green was a little slower. The human-intended suit, adapted to Feathers’ physiology – hastily, and with much guesswork about the functions of Feathers’ body in extreme conditions – was never going to be as finely tuned as it would be if there was a human inside. But it seemed OK for now, and she called that out.

  ‘Good,’ Meriel said. ‘Everybody seems fine.’

  Doria called, ‘Umm, I’m following the light show with my own external monitors. I think it’s safe to look out now. If you have any trouble seeing, any at all, or if there are any other radiation alarms in your suit—’

  ‘Got it,’ Vasta said.

  Now Salma dared to allow her faceplate to clear to what seemed like transparency, but actually was, she knew, a heavily edited, reduced-intensity rendering of the reality.

  The sky, another new sky, was a wash of light.

  She saw an array of stars, shining brightly through a gas cloud, which itself was turbulent, frothy, multi-coloured, illuminated from within by yet more stars – as if boiling, but caught in a freeze-frame image. A barrage of stationary light, hanging over the ground of this dull grey, worn-out world, a turmoil on superhuman scales of time and space.

  But there was a sense of depth. Some of those embedded stars seemed close, while others shone through layers of the cloud, through curtains of turbulent gas and debris. All frozen still.

  And in among that stilled chaos, Salma thought she could see a tinge of green. Starlight, as if filtered through the green of the grasses and leafy plants in Meriel’s hydroponic farm. How could that be …?

  It occurred to her to look around at her companions.

  Doria, a few paces away, was looking down at the ground, in fact. Tapping her booted foot. ‘Looks like the same unprepossessing planet. A constant in all this – transition. Even colder, if that’s possible. And our heap of gear came with us, I’m glad to say.’

  Vasta seemed to chuckle. ‘That’s a lunar for you,’ she said. ‘Always aware of what’s under her feet rather than what’s in the sky.’

  Meriel snorted. ‘And that’s an Earther for you, is it? Always categorising, sneering—’

  ‘Forget it,’ Doria snapped. ‘Offensive she may be, but she does have a point. We all need an anchor in this – unreality. But I have a point too, don’t I? The ground underfoot hasn’t changed so far as I can see. Somehow we’ve been riding this world as it has been brought to – to this place, this other universe, I guess. So at least we have some kind of stability amid all this chaos.’ She seemed to have to force herself to stare up at the stars. ‘Under a sky like a frozen explosion,’ she said softly.

  Terminus appeared to have witnessed their emergence calmly. It said, Such transitions can be destabilising. In fact such young universes as yours are more amenable to interconnections through the higher dimensions. Engineering is more feasible—

  ‘Park it,’ Vasta said.

  She lifted her head, and Salma saw how the gaudy stars were reflected in her visor.

  ‘All right,’ Vasta said now. ‘I’ve managed a quick survey of our latest new sky. And those are young-universe stars, are they not? Just as we saw when we first arrived on Feathers’ world. Or rather, they’re the kind of stars a young universe creates. Though this isn’t my field. Have we gone back in time again?’

  Terminus seemed to think that over.

  Your thinking is limited.

  Vasta frowned. ‘Limited? I’m talking about time travel!’

  Salma was still hugging Feathers close, though more gently. She tried to take all this in. ‘So is this … place … very young? Compared to our universe. If those stars are like the early stars at home, Elizabeth … If that’s true, why all the green?’

  Vasta frowned, her expression visible through her faceplate. She looked up at the sky – and clearly picked out those huddles of stars Salma had noticed, with the greenish tinge.