Xeelee Redemption

by Baxter, Stephen

  Asher said, ‘We can’t be sure of the interpretation—’

  ‘Look, I’ll jump to conclusions, if nobody else will. All the way out there, the Xeelee are building a tremendous artefact, in the middle of intergalactic space. So big it’s distorting the entire structure of the cosmos around it. And creatures of dark matter are trying to stop them. That’s how it looks to me.’

  Jophiel shook his head. ‘It’s unbelievable . . . But if that’s anywhere close to right, it shows that the war we’re engaged in here – humanity’s war with the Xeelee – is only a fraction of the bigger picture. A detail.’

  ‘But a significant detail, maybe,’ Asher said. She smiled. ‘Questions?’

  The meeting soon wound up after that. Jophiel knew he would spend a lot of time considering what he’d learned. Not least about himself. And Michael Poole.

  They stood together, awkward mirror images.

  Aside from the two of them, only Nicola remained.

  Michael glared at her. ‘Staying to gloat?’

  ‘About what? Your personal angst? Look, Poole, from the minute that Xeelee poked its nose out of your wormhole it’s obvious you’ve been mired in a tangled mess of overwhelming moral complexity. You’re central to it, but it’s not your fault. How could it be? Self-pity, in you, is a sign of arrogance.’

  Jophiel had to laugh. ‘Is that supposed to comfort us, Nicola? Maybe you should stick to the tough talk.’

  She grinned. ‘Fair enough. Well, here you are on a twenty-five-thousand-year punitive mission to the centre of the Galaxy, and that is your fault. You may be one of the few military despots in history who isn’t actually a psychopath. No wonder you are screwed up.’

  And she popped out of existence.

  Two days later, with the turnover complete, the GUTdrive was smoothly restarted, and an agonisingly slow deceleration began.

  FOUR

  This is a key time in human history, Alia, a high-water mark of human ambition. We’ve been privileged to see it, I suppose. But now we must fall back.

  Luru Parz, c. ad 500,000

  33

  Ship elapsed time since launch: 16 years 328 days

  Earth date: c. ad 28,700

  It took six more years by crew time – as nearly thirteen thousand more years passed, beyond the ship’s hull – before the Cauchy reached the Central Star Mass, the crowded space at the very heart of the ten-thousand-light-years-wide bulge of stars at the inner terminus of the great spiral star-lanes of the disc – a bulge that, Jophiel knew, the Exultant generation would have called ‘the Core’.

  And then ten more months’ ship time, ten months in increasingly star-crowded skies, before the ship neared its next significant astrophysical landmark, known as the ‘Cavity’, a kind of spherical bubble of relatively low density, at the centre of which lay the black hole itself.

  On the day the ship reached the edge of the Cavity, Asher summoned the seniors to the apex office. When Jophiel got there Asher was waiting, her old-young face blank, illuminated by the complex light of the Galaxy Core. She had been unusually vague about what was on her mind, Jophiel thought.

  A Virtual Nicola was here too, as ever captivated by the view beyond the lifedome.

  And that view . . .

  Jophiel struggled to find words to describe it, A crowded sky that reflected from Nicola’s Virtual silvered face. As ever, the view was an image unfolded from light aberration: even after years of deceleration the Cauchy, was still pressed hard against the light limit in its forward travel.

  The others, too, were hushed.

  ‘Take a starry night on Earth,’ Nicola said at length. ‘Somewhere clear. A high desert in South America, where the Anthropocene-era astronomers built their great telescopes. Or, better yet, a still, cold night on Mars. Between dust storms anyhow. Just you and the stars. That’s the kind of sky we evolved under, I guess. The kind of sky we’re used to. Stars, a few thousand clearly visible to the average eye, in clear, familiar patterns that barely change in a human lifetime.

  ‘Then double it.

  ‘Overlay it. Again and again and again. Fill in all the gaps with stars, and vast, glowing dust clouds. And do it over again until the sky everywhere you look is deep with stars, the nearer ones sliding visibly over your field of view . . .’

  Asher nodded. ‘You know that we’re close to the destination now. Only seven light years from Chandra, the black hole itself. Only three years of ship’s time before we slow to zero. We are well inside the Central Star Mass. Ten million stars, in a volume of space that might hold ten thousand out in the vicinity of Sol. And from here on in it’s going to get even more crowded.’

  ‘Because we’re falling into the gravity well of the central black hole,’ Nicola said.

  ‘That’s it. But even before we get there, we’re learning an enormous amount about stellar evolution.’

  Jophiel grinned. ‘And everything we thought we knew was wrong.’

  Asher shrugged. ‘How did you guess? You know that we are at the edge of the Cavity. That’s the name the Exultants seem to have given this place, when this was a war zone. A kind of gap in the heart of the Galaxy, centred on Chandra – well, everything is centred on the black hole. A gap fifteen light years across.’

  She expanded a patch of the complex sky, a patch scattered with stars and glowing clouds. In there was even what seemed to be a spiral structure, Jophiel thought, tangled lanes of stars and dust, quite distinct, like a fractal model of the Galaxy itself, here at its heart.

  And at the very centre, a point of intense light.

  ‘That is Chandra,’ Asher said now. ‘That central pinpoint. The black hole. You can’t see the event horizon yet, because it’s embedded in a cloud of stars, something like ten million of them within a light year. “Chandra” is another Exultant name, by the way. Like the “Baby Spiral”, for that feature you see.’

  Jophiel only half-listened. He, and he suspected Michael, was gazing at the black hole and its surrounds, looking for traces of the Wheel, as they had come to call the artefact in the amulet, the band around the black hole. Not yet visible. Not yet.

  Asher said, ‘Outside this Cavity there is a steady infalling of gas and dust – falling into the black hole’s gravity well, that is. But there are a dozen or so superbright stars deep inside the Cavity, orbiting the black hole, which emit a ferocious stellar wind that pushes the infall back. Just a dozen stars, their energies sweeping this huge volume clear . . .

  ‘So, behind us, there is a torus of molecular gases, relatively dense, where the infall is stalled by the starlight. The arrangement isn’t particularly stable. Every hundred million years or so there’s a loss of stability, a collapse of the torus, a burst of star formation.

  ‘What we don’t find here in the Cavity is any evidence of dark matter. And not as much modification of the stars as we’ve seen out in the spiral arms. None of the accelerated ageing. But—’

  ‘Whoa,’ Nicola said. ‘You’re running ahead of us. You’ve seen the stars ageing?’

  Asher looked uncertain, Jophiel thought. Self-conscious. ‘Sorry. It’s just that we’ve learned so much, these last years, months – we lose track of what we’ve briefed. But, yes. We have been travelling for twenty-five thousand years, nearly, as measured in the external universe. And that’s long enough to actually see some modification. In individual stars, I mean. Stars growing old too fast.’

  ‘Ageing,’ Poole said. ‘Just as we suspected in the Sun. The photino fish clogging up the stars’ fusion cores with helium ash. Pushing the stars towards the end of their lives too quickly—’

  ‘How long?’ Jophiel asked. ‘How long until the stars die?’

  ‘I can only tell you what we’ve observed,’ Asher said cautiously. ‘In twenty-five thousand years of travel, we think we’ve seen individual stars we’ve monitored age as much as they should
in twenty-five million. The luminosity changes, the spectral profile—’

  ‘A factor of a thousand,’ Nicola said. ‘So a star like the Sun, which is five billion years old, and should have billions more years ahead of it—’

  ‘Only millions.’ Asher laughed, hollowly. ‘Sounds a lot. It’s not. A million years is the age of the human genus, for instance. And we think we know why this is happening. I told you. It’s not about physics. It’s about life. No. Belay that. War. It’s about war.’

  A startled silence.

  Poole asked, ‘What war?’

  ‘Just listen.’

  In the beginning was the Big Bang.

  Nothing but physics at first, Asher said, an unravelling of physical law, the crystallisation of matter from energy.

  But life soon emerged. The Xeelee, from the tangled spacetime of the first splinters of time. Thus, one protagonist of the longest war.

  The other soon followed.

  ‘We don’t know when dark-matter life first emerged,’ Asher said. ‘But we think it was very early – and we think we do know what the first structures of dark matter in the universe must have been. Immense stars, or starlike objects – from a hundred to a thousand times as massive as the Sun, generating heat purely from their gravitational collapse, and their own subtle internal forces – there are no fusion processes as in the cores of stars, not in dark matter. Different physic-al forces, remember. Still, clouds as bright as the Sun.

  ‘Which in turn quickly collapsed to create black holes. Objects which slowly merged in turn to create the supermassive black holes like Chandra, here. Which in their turn gathered galactic masses, of light matter, around themselves.’

  ‘Mm,’ said Poole, wondering. ‘And the black holes attracted the attention of the Xeelee.’

  ‘We think so,’ Asher said. ‘The Xeelee are creatures of twisted spacetime themselves – relics of an even earlier cosmic era, probably. They would surely be attracted to the event horizons of the new, giant black holes.

  ‘Perhaps that was the first interaction between Xeelee and dark-matter life. It wouldn’t be the last.

  ‘Because by then, you see, we believe dark-matter life was evolving quickly.

  ‘The first true stars were born around six hundred million years after the Big Bang. Which would one day generate baryonic life on the planets they warmed.’

  Nicola was nodding. ‘But they were also useful for the dark-matter creatures.’

  ‘Yes. As we know. With stars, for the first time in the history of the universe, you suddenly had small, deep and accessible gravity wells. And we think that dark-matter life quickly evolved to take advantage of that. Life on a tremendous, extragalactic scale, but with their breeding pools in individual stars.

  ‘We think that once this form of life evolved it spread quickly. Probably faster than light, actually; we think it’s most likely they used natural wormholes, another kind of defect left over from the Big Bang. Today, now we know what to look for, we see dark-matter fingerprints everywhere, in the stars of very distant galaxies.’

  ‘And meanwhile,’ Michael Poole said heavily, ‘the stars evolved, and the planets stabilised, and in warm puddles on worlds like Earth—’

  ‘Life evolved,’ Asher said. ‘Baryonic life, like our own. Busily breeding under the light of stable stars.’

  Nicola prompted, ‘Except—’

  ‘Except the stars weren’t all that stable after all.’

  The great dark-matter Ancients had believed they ruled the universe. But their domain had flaws.

  These pesky stars, with their so useful breeding-pond pinprick gravity wells, had an unfortunate propensity to blow up.

  ‘Oh, they don’t all explode,’ Asher said. ‘But even calm, sensible stars like the Sun will age. But here’s the kicker. Only about a tenth of the hydrogen fuel available in the star is used up in the process.’

  ‘Which wasn’t good enough, for the lords of creation,’ Jophiel said.

  ‘Right. Inefficient. And they probably didn’t much enjoy the explosions and expansions going on in their cosy little breeding pools. Novas and supernovas and such.

  ‘And so we think – we think – the dark-matter Ancients began to tinker with the workings of the stars.

  ‘At first they may have tried to make them more efficient, more stable. Lift away a little mass: smaller stars burn longer. Mix up the inner layers so more of that hydrogen fuel reaches the fusion engine: another way to stretch the lifetime of a star.’

  Jophiel nodded grudgingly. ‘And they do all this through the photino fish.’

  ‘That’s it,’ Asher said, nodding. ‘We think they must do it all through gravity – which is accessible to them. Flocks of photino fish wheeling in the cores of stars, spinning them up for mass loss, diverting mass flows in the interiors. Maybe the photino fish, basically a larval stage, evolved into a separate subspecies, a companion life form, to achieve all this.’

  ‘Ah,’ Jophiel said, grinning. Enjoying the play of ideas. ‘But these tinkering Ancients had rivals as lords of creation, didn’t they? Who might not have liked to see such widespread meddling with the light stuff, the baryonic matter – their own domain.’

  ‘The baryonic lords,’ Nicola said, rolling the words around her mouth. ‘I like that. The Xeelee. There must have been a first confrontation. Xeelee against dark-matter creatures.’

  Jophiel mused, ‘If Max were here, he might be asking how you would fight a dark-matter enemy. If you had to, theoretically. Bullets, shells, energy beams would just pass through them. But, gravity—’

  ‘Planetbusters,’ Poole said flatly. ‘That’s it. Gravity is all that could touch them.’ His eyes widened. ‘Hey. No wonder the Xeelee have planetbuster beams. Like gravity-wave lasers. The planetbuster wasn’t designed to smash up our planets. It was designed to take on dark-matter creatures. It was a weapon from a much older war than their conflict with us.’

  Jophiel grunted. ‘So, the Xeelee pushed back. Across the Galaxy, presumably. Across the cosmos? Lethe. It’s unimaginable.’

  Nicola mused, ‘Makes you wonder if maybe we picked the wrong side to root for in this war in heaven.’

  Poole’s face was set. ‘It was the Xeelee that attacked Earth. Not your dark-matter Ancients.’

  ‘Good point,’ Nicola said drily.

  ‘Anyhow,’ Asher said, ‘at some point the Ancients changed their strategy. Now they targeted the big, bright stars, like the Sun. Infested their cores. And they started to shorten their life cycles, driving them to an early termination. You can see the logic. In one stroke they can eliminate baryonic life, and get rid of such stellar inconveniences as supernova explosions. The prize would be a universe full of cosy, safe, sterilised relics – a trillion years of stability, or more. Once they get the job done. They probably left most of the stars untouched, actually. The small ones, the red dwarfs – they were fine for the dark-matter life cycle.’

  ‘One thing I don’t understand,’ Jophiel said. ‘The stars are billions of years old. Once the Ancients finish their remodelling, the stars will have just millions of years of main-sequence life left. So this star-tampering strategy can only have begun recently—’

  ‘“Recently” as an astrophysicist defines it,’ Nicola said drily.

  ‘Right. Meaning, millions of years ago, not billions. And it will be over in a few millions more years, not billions. So how come we are around to see it? Seems a coincidence that we evolved just as a war as old as the universe comes to its climax.’

  ‘Not really,’ Asher said gently. ‘We think it’s about efficiency. Look – the universe has an unknown future ahead of it. But already its age of star-making is coming to an end, in a sense, even without the Ancients’ meddling. All the easily accessible star stuff, the hydrogen in the discs of the galaxies, is being used up. We think that nineteen out of twenty of all the stars
that ever will be born, have been born already.

  ‘And we think the Ancients have waited for this moment, waited for the maximum number of stars to be ready to be modified, in one grand sweep.’

  Poole pressed, ‘And as for us?’

  Asher shrugged. ‘It may have taken this long too for life like ours to have emerged, even after stars and planets were born. The long slow process of evolution from some chemical-rich scum in a warm, drying pond, to starships . . . So there’s some coincidence about the timing, but not as much as you might think.’

  ‘Lethe,’ said Nicola. ‘So they mount a universe-wide campaign of this star-ageing, all at once.’

  Asher said cautiously, ‘We’re still – guessing. We now have data spanning twenty millennia or more. But even so, it’s like a single snapshot in a war that reaches back to the birth of the universe. We think we’ve got this right . . .’

  ‘But this doesn’t change our basic objective,’ Poole said now. ‘Which is our encounter with the Xeelee from the Solar System, in whatever lair it inhabits there.’ He pointed to Chandra, the black hole, and its attendant cloud of captive stars. ‘We’re still seven light years out. Three years left to travel. Three years we must use to prepare, for the end game.’

  That killed the conversation. The others drifted out, one by one. Jophiel looked back at Poole, who stayed there, alone, staring at the complex Galaxy-hub sky.

  34

  The journey continued.

  Time passed.

  And on the two hundred and fifty-second day of the twentieth year of the flight, Michael Poole called Jophiel to his apex suite.

  The GUTdrive had died away now; they were weightless once more, for the first time since the turnaround ten years earlier. And in the last months, as the Cauchy shed its velocity, the aberration of light had finally unravelled, and the sky began to look normal once more.