Xeelee: Endurance

AD 5274

1

Chael smiled at Mara. Beside Chael stood the sullen Engineer he had introduced only as Tasqer. And with them, in Mara’s living room, stood the Virtual avatar of Jasoft Parz, probably the most powerful human being in the Qax dominion of mankind.

Mara had never trusted Chael, her husband’s brother, even before Pell had died, and she didn’t trust him now. But here he was with these extraordinary characters, telling her about the most outlandish project she’d ever heard of.

A project to which, it seemed, her own son Juq was somehow the key.

‘We even have a name for the ship we’re going to build,’ Chael said.

‘The ship you’re going to build for the Qax,’ Mara pointed out.

‘For the Qax, yes. Everything we do is for the Qax. But this is a chance for humans to achieve something for themselves, under the yoke of the Occupation – even with the encouragement of the Qax Governor—’

‘The ship you want my son and his toys to contribute to, somehow.’

The unreal spectre of Jasoft Parz, Ambassador to the Qax, smiled with an odd serenity. ‘Time is short, Mara. The Governor wants this craft, a Poole-technology GUTship towing a navigable wormhole mouth, built and launched within six months. GUTship engineers we have . . .’

And he nodded to the taciturn Tasqer, the Engineer. In dark, practical-looking clothes, Tasqer was perhaps forty, and though heavy-set he had the pallid look of the space-born. Since this little party had come floating down to Mellborn in a flitter from the sky, Tasqer had said not a word, and he said nothing now, meeting Mara’s gaze coolly.

‘But,’ Parz went on, ‘wormhole builders are another matter. And so when my old friend Chael here came to me and pointed out your son’s experiments . . .’

Mara found it difficult even to listen to this nonsense. Jasoft Parz himself was a distracting presence. Parz looked around seventy years old, with a round face, white hair, finely robed. But he moved with the ease of a younger man, Mara thought suspiciously. She looked at him more closely.

And were there black roots showing under that mop of white?

She tried to suppress her reaction, the shock of recognition. But Parz smiled at her. He wasn’t hard to read – or rather, he was more than skilful at projecting his true meaning. Yes, he was saying, she saw suddenly, that through this strange scheme the ultimate prize was indeed available: AntiSenescence treatment. Life itself. All she had to do was play along.

Suddenly Mara’s attention was fully focused.

Chael said now, ‘Juq’s experiments, yes. Young people building spacetime wormholes in their bedrooms and back yards! It’s a remarkable story – it turns out there’s a kind of global craze for such things, loose societies of enthusiasts communicating and sharing. It’s just like the rocket clubs that formed before the first age of space.’

Parz said, ‘Well, not all the ingenuity mankind showed in the heroic days of Michael Poole has been lost, evidently. Here is something we can build on. And your son, Mara, is in the vanguard of developments.’

Actually, Mara thought, not so much her son, not handsome, plausible Juq, but his smarter but lower-class buddy Tiel. She wasn’t so blinded by her love for her son that she couldn’t see where the brains in that partnership lay.

Chael said, ‘We see Juq as a potential leader of this aspect of the project, young as he is.’

She eyed her brother-in-law, and Parz. That made sense, at least. ‘Hm. A bright, good-looking son of an old military family? Yes, he’d be a good front for this operation, wouldn’t he? You’ve an eye for figureheads if nothing else, Ambassador.’

Chael said seriously, ‘It’s not a trivial point. Image matters. Both my family and yours, Mara, do have respectable pedigrees dating back to Navy service in the days of the rebellion against the Squeem.’

Parz said carefully, ‘And now you serve in a different way, as I strive to do, in making life bearable for billions under the administration of the Qax.’

Of course that was true, in its way. When the Qax had almost effortlessly taken over the Solar System, rich old families like Mara’s, seamlessly embedded in hierarchies of wealth, privilege and power, had seemed to find it easy to transfer their loyalties to the new alien rulers. Their justification was that without their selfless negotiating with the Qax, the lot of the rest of mankind could be considerably worse.

But especially since Juq had started bringing his friend Tiel home to play with their wormhole experiments – and Tiel had let leak a few details of the lives he and his family led, brief lives spent labouring on the coastal algae farms, or on the great sea-bound transport canals and sewage ducts, until ending in old age or terminated by diseases that had once been banished from Earth – Mara had become uncomfortably aware, here in her grand home in the heart of ancient Mellborn, what privileges she and her family enjoyed, and how morally compromised she had become . . .

Yet she looked again at those odd black roots under Parz’s white hair. The most cruel imposition of the Qax regime, like the Squeem before them, had been the removal of AntiSenescence treatments, which for millennia had enabled humans to postpone death. Though there were endless rumours of illicit sources of AS, and of secret groups of undying living among mortal humans, not even the most senior in the Qax’s human administration had legal access to such treatments. In theory. Now it seemed that wasn’t true. What was she being drawn into here? And – could she refuse the implicit offer, for herself and her family?

Jasoft Parz caught her looking at him, and smiled again.

‘Well,’ she said briskly. ‘Before we go any further with this conversation you’d better come meet the boys and see if what they’re building is actually any use to you. The staircase down to the cellar is this way . . .’

The townhouse was very ancient, and the cellar more so, perhaps millennia old, Mara suspected. But she’d had it renovated recently. Hovering light globes made the roomy chamber bright as day, illuminating walls now overlaid with the boys’ images of the heroic days of wormhole-building when Michael Poole and his colleagues had laced the Solar System with their faster-than-light transit tunnels.

Both Juq and Tiel waited for them here, dressed in clean coveralls, standing beside the long table on which they’d set up their latest experiment. The neatness had been Mara’s mandate; she wanted them to look like smart young engineers, not teenage hobbyists. They would always be an ill-matched pair, however. Though at seventeen Tiel was a year older than Juq, he was a good head shorter than Mara’s son, no doubt some consequence of diet and upbringing.

The Virtual Jasoft Parz greeted Juq with a smile. ‘It’s good to meet you, my boy. I did know your father – a good man.’ He spread his hands. ‘And I’m sorry I can’t be here in person.’

‘I’m pleased to meet you too, sir.’

Juq, tall, blond, blue-eyed, handsome, had never been short of confidence, Mara knew, even if he had never been academic. And he was instantly likeable, as she could see despite her mother’s bias. She’d never had any doubt that with such attributes, coming from such a family, he’d find a place in the world. But she’d never expected him to be caught up in spacecraft experiments – or at least she’d imagined it would be nothing but a boyhood fad . . .

Parz glanced around. ‘I’m surprised to find you working in a cellar. Why not above ground, in the daylight?’

Tiel and Juq glanced at each other uneasily.

Chael stepped forward. ‘Call it caution, Ambassador. I know from my own fond memories that my nephew here has been fascinated by the Poole era since he was small. Books, dramas, even the imagery you see here on these walls. We saw no harm in it – we should be proud of the human past – even if the Squeem did shut down the old Poole tunnels long before any of us were born. Then when he found it was possible, in principle, to build a wormhole in a home workshop—’

Juq took over. ‘Sir, I know experiments with spacecraft technologies are indicted under the Occupation.’ He glanced over at Tasqer the Engineer, who gazed back. ‘I wasn’t sure if this qualified. After all, a wormhole isn’t spaceflight technology in itself; in fact, to use a wormhole to travel through space, you would have to use a spacecraft to tug the Interfaces into position. But I didn’t want to get my family into trouble.’

Parz nodded. ‘And so you hid it all away down here.’

Juq squared his shoulders. ‘I am prepared to take full responsibility for any breach of regulations, Ambassador.’

Chael beamed. ‘You see, Jasoft? You remember what I told you about this boy? Smart, intelligent, and morally upright. What a credit to the family, to the race!’

Parz gave Mara the slightest of smiles, showing he wasn’t entirely taken in by this salesmanship. But Mara couldn’t blame Chael, she supposed, for working so hard to obtain for the family any benefits that might accrue from this peculiar opportunity.

Parz said now, ‘Perhaps you’d better show me this marvellous experiment of yours.’

Juq led him to the table, where Tiel stood waiting. Juq said, ‘Maybe you’d be best at talking the Ambassador through it, buddy.’

Suddenly Tiel looked terrified. Mara imagined the only figures of authority who had spoken to him before had been work supervisors and police. He opened and closed his mouth, and said, ‘Sir – Ambassador—’

‘Take your time,’ said Parz kindly. He stepped up to the table, which was low and long and topped by an airtight transparent cover, and cluttered with heaps of equipment. Parz passed a Virtual hand through the cover, making blocky pixels sparkle. ‘I understand this is a mere model.’

‘But it is a fully functioning wormhole,’ said Tiel, more confidently now. ‘A flaw in spacetime that enables faster-than-light travel from one end of the table to the other. You can’t see the Interfaces, of course, they’re microscopic. And all we can pass through is laser light. But—’

‘But the wormhole is stable, yes? I understand that’s the trick, the hard part. Wormholes tend to collapse on themselves—’

Tiel said too quickly, ‘In fact they get locked into causal feedback loops and detonate.’

‘You need a kind of antigravity to keep the wormhole throat open – is that correct?’

‘Yes, sir,’ Juq said. ‘More precisely you need what’s called “exotic matter”, a peculiar kind of matter with a negative energy density. Yes, it works like antigravity.’

By now even Mara had been forced to learn how wormholes worked – in particular that a wormhole without exotic matter in its throat was useless. Lethal tidal forces would bar the wormhole portals, the portals themselves would expand or collapse at light-speed, and the smallest perturbations caused by any infalling matter would result in instability and collapse. So, in their designs centuries ago, Poole’s team had learned to thread each of their wormholes with ‘exotic matter’, to provide an antigravity effect in the throat to keep it open. The wormhole was still intrinsically unstable, but with feedback loops it could be made self-regulating – but the negative energy levels Poole had needed were high, equivalent to the pressure at the heart of a neutron star. It had been a challenge for Poole, and was a challenge now.

Parz said, ‘I do know that fifteen centuries ago Michael Poole harvested his exotic matter from the orbit of Jupiter. Whereas here—’

‘We’ve had to be more subtle,’ Juq said.

Tiel said, ‘Actually, I had the idea when I was working on a landfill processing detail.’ Combing through millennia-old garbage, Mara knew, for reusable materials, chemicals, even artefacts; all over the planet the occupying authorities had people sifting the debris of their own past for materials the Qax could sell off-world. ‘And I found these.’ Tiel held up threads of very fine fibre on the palm of his hand. ‘There are splinters of diamond attached to these optic fibres, sir. Very small, very fine. I have no idea what kind of machine these came from, once. But I realised that with these I could make—’

Juq put in, ‘He got the proper permissions before removing the materials from the site, Ambassador. The threads were of no discernible value and had no weaponising potential.’

Parz waved a hand. ‘Yes, yes. Just tell me what you did, boy.’

‘It’s technical, sir. At the quantum level all matter and energy, a beam of photons say, is naturally a mixture of positive and negative energy. Although the net balance is always positive, overall.’

‘All right. This positive energy is the ordinary stuff we use to heat our homes and power our flitters?’

‘Yes, sir. And negative energy is – well, it’s a gap where energy ought to be. And it’s equivalent to exotic matter. In a way – the mathematics is subtle . . . What you have to do is squeeze the vacuum – that’s the phrase we use – so that the negative component of the energy is separated out, and can be gathered. Here we do that by using the diamond splinters to manipulate photons in a light beam one by one. And we capture the negative energy in a mirrored cavity, which—’

Mara thought Jasoft’s eyes were glazing over. ‘Maybe you’d better just show the Ambassador how it works, Tiel.’

In fact, much of the experiment had to be taken on faith, since the wormhole mouths were too small to see. The boys had set up two fine laser beams, passing through a narrow vacuum chamber set up on the table: beams which cast spots of ruby light on a plate at the table’s far end. One beam was passed unimpeded, the boys said; the other was sent through a wormhole a metre long. And the photons in the second beam, travelling instantaneously between the wormholes’ tiny Interfaces, took a few nanoseconds less to travel the length of the table: a small interval, but sufficient for the boys to demonstrate with a precise clock.

‘I’m impressed,’ Jasoft Parz said. ‘Junk from a landfill, a home workshop – and you’ve built a stable wormhole. Very impressed.’

Chael beamed. ‘Told you so, Ambassador.’

Mara stepped forward. ‘Well, I’m still in the dark. Even if it’s possible somehow to scale all this up from a tabletop . . . The Qax want us to replicate Poole’s work, correct? To build a navigable wormhole, and then to drag one end across space in a slower-than-light GUTship. Why do they want to do this? And why a GUTship? It was great technology fifteen hundred years ago, but those ships are slower than light. The Qax have those Spline starships of theirs, capable of faster-than-light travel. So why would they want this?’

‘It certainly harks back to our past,’ Chael said quickly, evading the question, and evidently anxious to reassure the Ambassador. ‘Which is why it’s so valuable for morale. Hence my suggestion for the ship’s name, Endurance, used many times since but originally referring to a great exploration craft of the late second millennium—’

‘I can tell you what’s prompted the Qax to do this,’ said Engineer Tasqer, surprising them by speaking at all, Mara suspected. He stepped forward and searched the boys’ images on the wall. Most of them showed Poole and his colleagues, legendary names in their own right like Miriam Berg and Bill Dzik – faces with the eerie agelessness that came from decades of AS treatment, Mara thought, from a time when it was unimaginable that such a thing could ever be lost.

‘Here it is. Knew you boys would have got hold of a shot of this.’ Tasqer tapped an image, dark, grainy, much less impressive than the rest. But a glimmering tetrahedral form was clearly visible. ‘That,’ he said, ‘is a wormhole mouth. Poole era, a classic design. And this image isn’t fifteen hundred years old but, what, a month?’

Mara frowned, baffled. ‘A month old? How is that possible?’

‘This is Poole’s own design,’ Tasqer said. ‘Poole’s own ship! One of Poole’s last projects was to build a GUTship called the Cauchy, which he sent off on a fifteen-hundred-year loop out into space, towards the galactic centre. Towing a wormhole mouth, not to the planets, but to the stars and back. Fifteen hundred years, you see. The flight plan predicted it should arrive back home about now – we knew that, and looked out for it – and here it is, right on schedule, out on the edge of interstellar space. That’s what inspired you kids to fool around with wormholes, right?’

Juq grinned. ‘How could we not, sir? An authentic Poole wormhole, returning to the Solar System . . . I suppose I should have told you we have this, Mother. But everybody’s got the image, everybody’s talking about it.’

Mara pursed her lips. ‘Well, I didn’t know about this. The Poole ship.’

Tasqer leaned forward. ‘This is obviously why the Qax suddenly want us to build another wormhole ship. Because of this ghost from the past. But to what end, Ambassador?’

Parz hesitated before replying. ‘It’s complicated. And frankly it’s best you know as little as necessary about this. All of you. I’m afraid that going forward with this you’ll need to be vetted by the security services.’

Mara didn’t like the sound of that. ‘Vetted? For what?’

‘For any links to seditious groups.’ He glanced at Tiel. ‘I know that some in your family, Tiel, have links to a group called the Friends of Wigner. You have a cousin called Shira who is currently—’

Juq put a protective arm around Tiel’s shoulders. ‘You don’t need to worry about that, Ambassador. Tiel can stay with us from now on – I’ll vouch for him.’

Tiel looked shocked at this sudden appropriation of his life, as well he might, Mara thought.

But Parz nodded thoughtfully. ‘Good, good. I’m sure it can all be arranged. But I urge you to be circumspect. Cautious. Well, gentlemen, I can see there’s a long way to go and no assurance of success. But I think we have a commission for you. Though I’m sure that to build a navigable wormhole will take more than scavenged lasers and a tabletop.’

Tiel nodded. ‘We’ll need to make more exotic matter. A lot of it. More than we can fudge up with scrap optic cables.’

‘And what do you think you’ll need to achieve that?’

Without hesitation Tiel replied, ‘A Squeem hyperdrive unit.’

The Engineer laughed out loud.

Parz, showing admirable composure, asked, ‘Is that all?’

‘No. Also Xeelee construction material.’

2

The flitter rose from Occupied Earth like a stone thrown from a blue bowl.

Like most Earthborn humans of her era, Mara had only rarely travelled above the atmosphere. Now, as the ship settled into a low check-out orbit, the glowing innocence of the planet took her breath away. Two centuries of Qax Occupation had left few visible scars on Earth’s surface – far fewer, in fact, than the damage wrought by humans themselves during their slow, haphazard rise to technological civilisation. Away from the cities like Mellborn, rewilded Australe was a pale green-brown, the colour of scrubland populated by herds of immense beasts: the colours of life, of nature. But still it was disturbing to see how the Qax-run plankton farms bordered the coast in lurid purple-green. And on the land, scattered and gleaming fields of glass marked mankind’s brief and inglorious struggle against the Qax – at the site of SydCity, for instance, which was still left abandoned.

Mara sat with the Virtual of Parz, who was politely making this ride into space with her. The louring Engineer Tasqer sat opposite. Chael was riding up front in the cockpit, a backup in this pilotless craft. A month after Parz had initiated the Endurance project they were on their way to the Moon, to inspect the experimental exotic-matter production facility to whose design Tiel and Juq had been contributing.

But to get to the Moon, first you had to leave Earth. And Parz’s expression, in the bright light of Earth, was complex, she thought.

He caught her watching, and smiled. ‘You’re wondering what I’m thinking.’

‘You must have made this journey many times. In the flesh, I mean—’

‘I always meant for the best, you know. I do know what people think of me. Given that the Qax Occupation was imposed on mankind over a century before I was even born, and given that I discovered I had certain diplomatic skills that spanned both communities, human and Qax, I thought I could find a way to do some good through negotiation. Mediation.’

Tasqer asked, ‘And do you think you succeeded? Look down there. That is not a human landscape.’

‘Maybe not,’ Mara felt compelled to put in. ‘But it could surely have been a lot worse. They say the Squeem occupation was more brutal, in some ways. Yes, there was a war; yes, we lost cities. The Qax forced their own food production system on us, as you can see from here. But since the Occupation was imposed, the Qax have allowed us to preserve our cultural treasures – the ancient heart of Mellborn, for instance. And much of this continent remains wild, green.’ Mara was proud of this aspect of her own people’s legacy. ‘The wild is there because humans brought it back, long before the Qax ever came. We reversed extinctions using genetic traces; we reconstructed ecologies lost when humans allowed themselves to overcrowd their world.’

Tasqer snorted. ‘The Qax only allowed all that to be preserved because they mine it for export. Exotic biochemistries sold to their alien markets, out there among the stars somewhere. They are more sophisticated than the Squeem, I’ll give them that. But they are conquerors just the same.’

Parz put in, ‘The Qax are essentially traders, you know; that’s their motivation for conquest.’

The Engineer laughed. ‘They trade in Earth’s riches while humans eat slop from the coastal farms. Once we built starships. Once a kid like Tiel would have been training up on hyperdrive, rather than crawling through sewers sifting garbage.’

Parz said sharply, ‘Well, Tiel is getting his chance now, isn’t he? And you Engineers seem to have long memories.’

‘Should we not? Somebody must remember, now the old ones are dying off . . .’

Mara had heard that was true. After two centuries, and with their AS treatment long ago curtailed, the last survivors of the pre-Qax era, the last to remember Earth as it had been before the alien Occupation, were being lost one by one.

‘We stayed independent,’ Tasqer said now. ‘We Engineers. I myself was born between planets. My ancestors fled Earth at the time of the Occupation war. With no place to land, the refugees ganged together their spacecraft and found ways to live, through trading, piloting, even a little mercenary soldiering.’

‘And banditry, when you dare,’ Parz said.

‘But you yourself are no longer free,’ Mara pointed out.

Tasqer shrugged. ‘I dared once too often. After my capture I parlayed imprisonment into service for the Qax. And here I am, building a GUTship for them.’

‘Just so,’ Parz said. ‘The Qax can be . . . benign.’

‘Maybe you people need to get out of your golden cages more often,’ Tasqer said. ‘To the Qax we are probably more valuable as sacks of exotic chemicals than as thinking beings.’

Mara shuddered at that.

‘Enough,’ snapped Parz. ‘You don’t have a monopoly on conscience, Tasqer. And after all, this is a moment of human triumph, against all the odds: we are travelling to see the great machinery that Mara’s son is assembling on the Moon – and all of it prompted by the return of Michael Poole’s starship from the past.’

Mara said, ‘I admit I don’t understand what the purpose of that flight was, what Poole hoped to achieve – a great circle in interstellar space?’

Parz smiled. ‘I’m no physicist myself. But as I understand it, Mara, what Poole was aiming for, having spent decades building wormhole bridges between the planets, was to build a bridge to the future . . .’

Poole’s peculiar time machine was built on a combination of two extraordinary physical phenomena.

The first was wormholes, flaws in space and time that connected points separated perhaps by light years with near-instantaneous passages of curved space. And the second was time dilation. As a ship accelerated close to the speed of light, its clocks slowed compared to those observed from its planet of origin. Its crew would age more slowly, as would any equipment they carried – such as a wormhole Interface.

Poole’s GUTship Cauchy had been dispatched on a long, near-light-speed jaunt in the direction of Sagittarius, towards the centre of the Galaxy. It had carried one terminus of a wormhole, whose other end remained in Jupiter orbit. The Cauchy was to return after a subjective century of flight but, thanks to time dilation effects, to a Solar System fifteen centuries older.

And that was the purpose of the project. When, after a century of subjective time, the Cauchy completed its circular tour, its hundred-year-old wormhole portal, delivered to the fifteen-hundred-years-hence date of AD 5274, would be linked to its hundred-year-old sibling, in Jovian orbit, back in the year AD 3829, a century after the ship’s launch. And then it would be possible, using the wormhole, to step in a few hours across fifteen centuries of time, forward or back.

Mara was astonished. ‘What audacity.’

‘What an experiment!’ Parz said with a grin.

‘Well, now the Cauchy is back. Has anybody tried using it yet? Either going back fifteen centuries – or has anybody come forward, from Poole’s era? And I would like to understand why the Qax’s response to this bizarre arrival has been to build another wormhole of their own.’

The Engineer and the Ambassador exchanged a glance.

‘Very well,’ Jasoft Parz said. ‘The immediate cause of the Qax’s action is that it is a response to – well, a rebellion. A minor one, but effective. I can speak openly of this because the event was visible to human observers, suitably equipped—’

‘I’ll say,’ the Engineer said with a grin. ‘It was a rogue craft, assembled in secret—’

‘Under a cultural monument,’ Parz said disapprovingly.

Tasqer said, ‘We don’t know who they were. But, yes, somebody managed to reach the Poole wormhole. They got off the Earth and out of the Solar System and through that time bridge, to the past. What do you think of that, lady? If they made it through, if it all worked as Poole designed, what will they be doing now, back there in history? What will they be saying of the Qax, or of you, Ambassador, to an independent mankind? What wave of new history is rolling towards us even now?’

Parz sniffed. ‘Their belief system struck me as so insane that I doubt they’ll make any difference at all.’

Mara frowned. ‘If they made it to the past, shouldn’t that show up in the records, in our histories?’

Parz said hesitantly, ‘There are some mentions of a great disruption at the time, which people called the Emergency. But our knowledge of history has been badly damaged, by the Starfall war, by the Squeem occupation – by the activities of the Qax too, though I’m convinced they aren’t trying to disrupt our knowledge of that era specifically. Anyhow, there’s nothing we can do about that, is there? All we can do—’

‘Is carry out the orders of the Qax,’ the Engineer finished sourly.

Mara said cautiously, ‘And exactly what are those orders? You still haven’t told me it all, have you?’

Tasqer glanced at Parz, as if for approval. Then he said, ‘The Qax want to do what Michael Poole did, Mara. Just as Poole built a wormhole bridge to his future – our present – so the Qax want to build another bridge, with the wormhole built by your sons and towed by this new ship, the Endurance – a bridge to their own future.’

The idea astonished Mara, and horrified her. ‘And what then?’

‘Well, we cannot know,’ Parz said softly. ‘I suspect even the Qax Governor, who ordered this, does not know, yet. But that is the project we have been given.’

The flitter swivelled, its main drive cutting in at last to push the craft to the Moon, and Mara watched as Earth fell away. Now she glimpsed huge Spline craft, three, four, five of them, fleshy spheres glistening with sensor bays and weapons pods and armed with starbreaker beams: living ships that bore the Qax overlords, cruising over the planet they dominated. It felt almost a relief as Earth diminished in her view, and the Spline were no longer visible.

The Mare Serenitatis turned out to be a plain of basaltic dust. Its human history was dominated by two monuments, one the relic of a vast circular particle accelerator some three thousand kilometres long that was thought to date from the Poole era, and the other an even older treasure, set like a jewel in its own preserved park to the eastern edge of the accelerator: the site of a primitive lander from Earth, one of the earliest, although whether robot or human, none of the party could remember.

There were still many humans living and working on the Moon, as on other colony worlds and moons around the System. Up to now the Qax had been content to let such off-world knots of humanity persist, as long as they did not interfere with the projects of the conquerors; the Earth itself, with its teeming billions and complex ecologies, was the prize, not a few work-shacks on airless moons. And, guided by Tiel and his primitive engineering instincts, the Endurance engineering effort had been brought to Serenitatis because of that huge old accelerator, which, though damaged during the Starfall war, still had powerful installations and infrastructures that could quickly be renovated and adapted for this new purpose.

Mara, uncomfortable in the low gravity, let her son guide her around the hulks of enormous machines in this cavernous facility, which for her taste was dimly lit by too few light globes. But against this background Juq looked good, as he did almost anywhere. He was wearing a kind of uniform he’d designed himself, a practical coverall with flashes on shoulder and lapels. The project had to have an identity, he said – with, he hadn’t needed to add, himself as the symbolic head. Mara saw how well he filled that role, a natural aristocrat who seemed to inspire by his very presence the workers brought here from across Earth and the lunar colonies. No wonder he had been elevated by Parz, who was nothing if not a wily player. And it seemed to Mara now that Juq was throwing himself into the project with real enthusiasm, for better or worse. Not for her son a consideration of moral ambiguities, she thought wistfully; technological toys were all he was interested in.

But for all Juq’s charm, it was Tiel who explained the intricacies of what they were doing here.

‘The challenges we face constructing wormholes are essentially the same as those faced by Michael Poole. But we have stuff even Michael Poole never had. Squeem hyperdrives, left over from their occupation.’

Tasqer grunted. ‘No doubt there’s quite a stockpile for you to use. The Qax are still impounding human spacecraft, even after two centuries. I worked on a yard in Korea myself, breaking down vessels, taking out the hyperdrive units.’

‘That must have been heartbreaking for you,’ Mara said.

He just looked back at her.

Jasoft Parz said, ‘I admit I’m confused as to why you need a hyperdrive unit, a faster-than-light technology, to manufacture exotic matter for another kind of faster-than-light link . . .’

Tiel was patient. Evidently he’d had to answer such questions many times before. ‘The hyperdrive works by manipulating spacetime – and if you do that, you’re automatically manipulating gravity. With a modified hyperdrive I’m able to construct a gravitational field optimised to squeeze the quantum vacuum in such a way that the negative-energy components of a given field are extracted far more efficiently than with the optical systems we used earlier. Soon we’ll be able to churn out exotic matter on an industrial scale.’

‘He always talks like this now,’ Juq put in with a kind of graceful admiration. It was a way, Mara saw, of making his own lack of ability a charming asset rather than a handicap. She marvelled at her son’s apparently unconscious skill.

‘Very well,’ Parz said. ‘And what of the Xeelee construction material you asked for?’

Tiel said, ‘Construction material is light, easily grown from any energy source, impermeable to most radiation fields, very strong . . . It is ideal for our project, which will require the quick construction of large facilities if we are to meet production targets.’

Chael rubbed his hands. ‘You hear that, Ambassador? The boy has the brain of a genius but the logistical judgement of a born manager. Well, you’ve seen our full report—’

‘I have. And you’ve done remarkably well, boys, you and the other like-minded enthusiasts we gathered here. You’ve even hit the timescale we set you, of just a month to get this proof-of-concept facility up and running. I’m happy to approve the roll-out to full production, here on the Moon and on other suitable off-world sites. And we’ve no time to lose. Michael Poole took forty years at Jupiter to manufacture the exotic matter for his Cauchy project. We have a mere five more months. But we’ll get it done, I have no doubt. Well done, boys.’ He started to clap his hands, and the others joined in. ‘Well done indeed!’

Only the Engineer refused to join in the gentle applause.

3

Another month and the Endurance, assembled in Earth orbit, was ready to fly.

The craft was a GUTship, a very ancient design, indeed a design that Michael Poole would have recognised. When finally assembled, Mara thought the Endurance looked something like a parasol of iron and ice. The canopy of the parasol was a habitable lifedome, and the ‘handle’ was the GUTdrive unit itself, embedded in a block of asteroid ice which served as reaction mass. The shaft of the parasol, separating the lifedome from the drive unit, was a kilometre-long spine of metal bristling with antennae and sensors.

This craft had been hastily assembled from components retrieved from the breakers’ yards, under the supervision of Engineer Tasqer. In a hundred subtle ways, as Mara observed when Juq gave her eager Virtual tours, the ship’s components showed their age. Every surface in the lifedome was scuffed and polished from use, and many of the major systems bore the scars of rebuilding.

But it worked. And Mara, Earthbound all her life, subject of an alien regime, had never really understood, not in her heart, that mere humans had once mastered such technologies as this.

She was to learn that the ship’s destinations were even more remarkable.

For the ship’s maiden voyage Juq was sent on a grand tour of the Solar System – and specifically the sites where exotic-matter production was rapidly being ramped up, on Luna, Mars, and Titan, moon of Saturn. The purpose was motivation, inspiration.

Though she did not accompany him, Mara watched over and over the excited reports that Juq sent back to her, via secure channels mediated by Jasoft Parz. Luna now fizzed with exotic-matter plants. The designers had settled on gigantic torus-shaped designs for their manufacturing facilities, eggshell blue like the exotic matter itself, and vivid against the grey-brown lunar dust. On Mars too, just a few days’ flight away for the Endurance, Mara glimpsed such toruses nestling near the ancient and still-inhabited cities of mankind: the capital, Kahra, and the great arcologies like Cydonia, pyramids on Mars that swarmed with people.

And then there was Titan.

Though on Earth she was more than a light-hour away from the Saturn system, Mara eagerly followed Virtual-feed reports as a flitter piloted by Tasqer dropped from the spine of the Endurance and dipped into Titan’s perpetual photochemical smog. Soon the brownish murk began to clear, and she made out a surface, far below, oddly Earthlike, with mountains of ice hard as basalt and oceans, lakes and rivers of liquid methane and ethane, richly polluted by hydrocarbons. Michael Poole himself had opened up Titan for resource exploration, and since not long after Poole’s time this had been the most populous world outside the orbit of Jupiter. Titan had cradled mankind’s most remote cities, and huge factory ships had sailed these complex oceans, trailing high, oily wakes; enough food had been manufactured in those giant ships to feed all of Earth. Well, the oceans were still there, and Mara let the ancient, familiar names roll through her head: there was the Kuiper Sea, the Galilei Archipelago, the Ocean of Huygens, James Maxwell Bay . . . Now Earth had to feed itself, for the Qax had shut down interplanetary human trade, and few ships sailed Titan’s seas.

But there were exotic-matter toruses here, just as on the Moon and Mars, huge blue structures beside the domes of the old cities – even of the capital, Port Cassini.

People on Titan had welcomed the exotic-matter project. It brought a purpose to life beyond mere subsistence on a more or less implacably hostile world. And as the flitter landed at sites like Port Cassini, Mara watched as her son led the party from Earth through civic receptions and rallies for the workers. Tall, bold, handsome, an aristocrat of a powerful old Navy family on Earth, Juq effortlessly dominated such events – although he always had his uncle Chael, the manipulative power behind the throne, at his side.

The Endurance project felt human and aspirational, just as Chael had promised. It seemed to Mara, a mere month after Parz had approved this huge expansion of the project, that nobody swept up in all the excitement cared that this was a project inspired and owned by the Qax, alien overlords of the Solar System.

Or that even now nobody really knew what this project was ultimately for. When she thought this over Mara felt flickers of a deep unease.

And meanwhile her son, in these heady days, was becoming famous.

It came as a shock when Jasoft Parz intervened again. Exotic matter production rates were still not sufficient.

This was despite the fact that the designers had by now found a way to use much less exotic matter than Poole had required to thread his wormholes. The relativistic equations that described wormholes were nonlinear and allowed for feedback effects; it was possible to use a small amount of exotic matter smartly, to produce a kind of shock wave that would propagate down a wormhole throat, enabling a much larger passageway to be held open for the same amount of material . . . Even despite such ingenuity, the production capacity was not enough.

It had been a first instinct to lodge the engineering of this high-energy spaceflight project away from the Earth, for safety reasons. Though good progress had been made, it was soon clear that the populations away from the home world would not be sufficient to achieve the Qax Governor’s target. ‘I remind you again that Michael Poole took forty years over the Cauchy,’ Parz said. ‘We have four more months . . .’

Parz commanded, on behalf of the Governor, that fabrication facilities be set up on the surface of the Earth itself. And when, just a few days later, an exotic-matter facility began to be constructed east of Mellborn’s city boundary, Mara’s unease deepened further.

4

Engineer Tasqer visited Mellborn alone.

He told Mara that he was here to begin consultation on the next stage of the project, which would entail collecting exotic-matter stocks from plants like Mellborn’s across the planet and shipping them to Jupiter’s orbit, where, like Michael Poole’s Cauchy long ago, the great new wormhole would be assembled. This alone was going to be a huge logistical exercise.

Mara hosted the man for the night. Then in the morning she escorted him out to the exotic-matter plant at Yarraranj, some fifty kilometres to the east of the city.

And at the end of the day, when his meetings were done, she walked with him along a waymarked trail, away from the gleaming new blue torus, and into the country beyond. The exotic-matter plant had been set far enough out of the city to be beyond the suburbs, in a landscape giving way to nature – or at least nature as reconstructed by ecologists and geneticists who predated Michael Poole, back in an age when humans had done their best to fix retrospectively the damage their ancestors had done to the Earth. This was an arid landscape – not as arid as Australe had once been, after millennia of humans burning back the bush, but still only sparsely covered by scrub and gum trees. And here and there tremendous beasts moved, their shadows clear in the intense sunlight. Mara recognised the profiles of huge, muscular kangaroos.

Against this setting, the powder blue of the Qax facility looked ugly and out of place.

To Mara’s amusement, Tasqer, a pilot of interplanetary craft born into a rebel stronghold between worlds, seemed remarkably uneasy to be walking out in the open, on the planet that was after all the home of mankind. Perhaps this was the secret, spiteful reason she’d insisted on taking this walk with him.

‘You’re safe, you know.’

There was a deep growl, almost subterranean.

He glanced around. ‘What was that?’

She was embarrassed that she wasn’t sure; she lived her own life in the city. ‘A diprotodon, I think. A big marsupial beast the size of a rhino.’

‘Of a what?’

‘The other really big beasts out here are the megalanias, a kind of giant lizard that will take on an adult diprotodon. And dinornis, big flightless birds.’ She eyed him. ‘But don’t think birds. Think dinosaurs.’ This didn’t make him look any more comfortable, she observed gleefully.

He glanced around. ‘And I guess these beasts are all made harmless in some way. Defanged. Conditioned, made unable to attack humans.’

‘Oh, no. What would be the point of that? Human fatalities are remarkably rare . . . Look, I’m kidding with you.’ She gestured at the trail, the sparse posts that lined it. ‘You’re fully protected; there are force fields, sonic barriers. The critters soon learn to keep away. And don’t you think what our ancestors achieved here was remarkable? Although of course the Paradoxa Collegiate reconstruction dates from an age when AS technology was becoming widely available, life spans were lengthening, and people started to think seriously of projects on very long timescales.’

He grunted. ‘Because they were suddenly liable to stick around to see the consequences of their actions. You do know your history, don’t you?’

She had always resented his jabs. ‘I know I have a privileged position under this Occupation. Myself and my family, but I do try to use that privilege for good. Such as, yes, keeping human history and culture alive.’

‘Good for you,’ he said dismissively.

She sighed. ‘Very well. So how was your day?’

‘The meetings went well enough, given the magnitude of what we’re trying to do, and the timescale we have to work to. Just months! I took a tour of the facility. So many people labouring in the fusion plants, the Xeelee construction-material parks, the extraction bays – all those containment pods full of exotic matter piling up on lift pallets. Did you know the Qax Governor is demanding a wormhole Interface even bigger than the one Poole used? A huge icosahedral design, big enough to swallow a Spline ship . . . Well. Things are going as well as they could be, but the exotic matter dribbles out of facilities like this, and we need countless tonnes up there at Jupiter.’

‘Hm. Chael tells me Jasoft Parz is running another recruitment round. More folk to be transferred from other duties to the exotic-matter plants.’

‘If we had more time we could roboticise the process properly. But we don’t have the time, and we do have lots of people, and that’s the resource that’s being applied to speed things up – especially now we’ve located these operations on Earth.’

‘I do wonder about the urgency of it all,’ Mara said. ‘Why the hurry? And what about safety?’

Tasqer didn’t speak. He was staring into the distance, to the west, towards the setting sun; he seemed distracted. Looking that way, Mara thought she could see a speck in the sky, some kind of aircraft on the way in.

‘Engineer?’

‘What?’

‘About safety?’ she repeated sharply.

‘Human safety? In the facility?’ He shrugged. ‘What about it? The Qax don’t care. The plant managers do their best.’

They walked on. She could hear a faint noise in the distance now, off to the west, where Tasqer had been looking: a hum of engines. That aircraft, whatever it was, coming in for a low approach. She said now, ‘I hear rumours.’

‘Rumours?’

‘I do talk to people, you know, I don’t hide away in my town house all the time. There are reports of indentured labour. People forced to work in particularly dangerous environments.’

He looked at her blankly. ‘Look, Mara, the Qax don’t want us. They don’t buy or sell us. What they do sell is the exotic biochemistry of creatures like your diprotodons and your gum trees. We are partially useful – slaves. And as such we are expendable, to them.’ He looked her in the eye. ‘And to me.’

She was shocked by that last remark, by his deadened tone as much as by the words.

And that engine noise was suddenly growing louder, becoming deafening.

The aircraft, an Earth-to-orbit flitter she saw now, was coming in low and flat above the ground. Heading straight towards the exotic-matter facility. There was some kind of heavy pod suspended beneath its belly—

‘Down!’ Without warning Tasqer grabbed her around the waist and pushed her to the floor.

Twisting to see, she saw the flitter pass overhead and then roar down on the facility.

‘Close your eyes!’ Tasqer yelled, holding her down, his arm around her shoulders. ‘Close them tight!’

The flash was visible even through closed lids.

Then came a wash of air, a hot wind, and the ground itself shuddered, as if some tremendous Pleistocene beast had been felled.

She twisted her head to look at Tasqer.

‘Stay down,’ Tasqer yelled again, over a continuing roar of noise.

‘You did this,’ she screamed. ‘You and your people. The Engineers!’

‘Hell, yes.’ He raised a face crumpled against the noise, the wind, the dust. ‘We still have a few ships the Qax don’t know about, hiding out in the asteroid belt and elsewhere. Yes, we did this. I did this. I got into the facility, set a targeting beacon, disabled the defences, such as they were. There should have been simultaneous strikes all across the planet. This is why I gave myself up and burrowed into your sick Earth society in the first place. All for this. If we can disrupt this insane new project of the Governor—’

‘But what do you think the response is going to be? Do you think the Governor will just give up? The Governor is going to replace all this with something even worse for us than what you just destroyed. Did you fools think of that? And what about the people you slaughtered, the innocents forced to work in there—’

‘We’re in a war for the future,’ he said.

‘Mankind is to be saved, but people are expendable, to you as to the Qax.’

‘We all must do what we have to do.’

She stood up. ‘I have some police authority. Engineer Tasqer, you’re under arrest.’

5

Chael invited Mara to join him on his weekly inspection tour of the new exotic-matter facility in the Mellborn urban area. After Yarraranj, Mara was deeply reluctant, but the way Chael phrased it she sensed this was a command, not an invitation.

Chael landed on the spacious lawn of the family’s villa, off Crun Strand, in an armoured flitter bearing two armed crew, and with the black cross on its upper surface that signified it to be a craft of the Occupation. Mara briskly boarded.

As the ship lifted, the looming sky-blue hulk of the brand new exotic-matter factory on Flind Strand was soon visible. The raid Tasqer had guided down to the facility to the east of Mellborn had not been unique; on that day, still only a month ago, a coordinated series of strikes from deep space had indeed hit facilities all around the planet. The Qax’s punishment of those responsible had been brutal, and their response decisive and swift. Now the urban centres were not to be spared. Within days, blue exotic-matter facilities like this one had bloomed in the very hearts of human cities, like malevolent mushrooms.

Chael swore at the sight of Flind Strand. ‘When the Governor announced he was moving the factories into the urban areas, we argued against using the historic city centres, at least. Parz himself spoke eloquently. After all, the Qax have spared cultural monuments in the past.’

‘One sees it glowing blue in the dark,’ Mara said now. ‘From all over the city. One hears the hum of the great engines day and night, the whoosh of flitters coming and going – why, the noise of its hasty construction was itself cacophonous. I cannot sleep.’

Her brother-in-law smiled. ‘I sympathise. But those in the work camps have it worse, you know.’

‘I can imagine.’

The flitter skimmed east now, and Mara could already see another blue torus standing squat on the horizon, another new exotic-matter plant, brilliant in the low morning sun. It was surrounded by a muddy brown scar, fenced off: the living area for the human community that had been forcibly brought here to serve the facility.

‘That’s the Took plant,’ Chael said. ‘There’s a ring of six around the city, Took, Parc, Cens, Spots, Nu, and Wills. We’ll see them all today. There have been incidents to handle at them all,’ and he sighed.

‘The city is too quiet,’ Mara said. ‘They took so many people, stripping out everybody but the most senior in the Diplomatic Corps and their families, and workers on the most basic facilities, the sewage and food ducts. I thought they would just take—’ She waved a hand. ‘Criminals. Prisoners. Those without work. But nobody has been spared. Even children.’

‘They took most of the best engineers also,’ Chael said. ‘The Governor no longer seems to care about breakdowns in essential systems – if a suburb here or there goes hungry. It’s the same across the planet, if that’s any consolation.’

‘To think that two centuries ago we were immortals and interstellar travellers, and now this. I heard Ambassador Parz tried to argue against the use of child labour, at least.’

Chael smiled, rueful. ‘You may know that since the Qax removed AS treatment, our population has boomed. Whether that’s a response to the loss of our immortality, or some deeper survival response to the stress of the Occupation, I couldn’t say. Whichever, we are a young society, rich in children. And now we’re paying the price for that. And of course, if you don’t use children the value of the workers as shields is diminished.’

She frowned. ‘Shields? What do you mean? Shields against what?’

‘Why, against further attacks, from space, from the ground.’ He eyed her. ‘Sometimes, dear sister-in-law, you seem so naive. That’s one reason the Qax built these facilities in the cities. To give the ragamuffins pause . . .’

Ragamuffins. That was a word she’d heard too often recently. It referred to those Earthbound who had always lived out of sight of the Qax and their Occupation, out of sight of their law and control. Earth was a big and complex planet and there was room for a few to hide – and, it seemed, to fight back. The Engineers had turned out to be just one faction of a wider resistance.

She hadn’t imagined she was still capable of being shocked. ‘People used as a shield. Why, that’s monstrous.’

‘There are limits even to Jasoft Parz’s powers of persuasion. And Parz may be compromised himself.’ He leaned closer. ‘I don’t think we’re being monitored in here . . . Did you know that Jasoft has a daughter?’

Again she was shocked. ‘A daughter? But – I’ve known him for a quarter of a century, since Pell and I started to work for the Corps. I never met a wife, a lover, let alone heard of a child.’

‘That’s because he doesn’t know himself. It’s one of the Qax’s more cunning ploys. They don’t breed as we do, you know; there seem to be only a few thousand of them, and they are effectively immortal. But they are capable of observing our mammalian breeding practices, and of manipulating them to get what they want of us – or at least of the most senior people, those whose betrayal they fear. Serve them and, if you have a child, they’ll take her from you, lodge her in some special school somewhere.’

‘A hostage.’

‘Exactly. And if like Jasoft you don’t have a child – and, though we never discussed this, I suspect he chose not to have children for this very reason – they make sure you have one anyway. It’s not difficult, after all. They have tame human geneticists, obstetricians—’

‘That’s monstrous.’

‘That’s the Qax. I’m told that Jasoft’s daughter is around twenty-five years old, and lives in North Amerik.’

She stared at him. ‘How do you know all this?’

‘I try to know everything. I figure it’s my best chance of surviving. I talk to everybody, even those on the wrong side of the Qax’s laws. Mostly, though, I just listen. You’d be surprised how much you can discover that way.’

‘And you haven’t told Jasoft?’

‘Would you? Maybe I will, some day. For now I don’t want to compromise him. He is too effective where he is.’

‘You’re a cold one.’

‘No. Just a survivor.’ The flitter began a slow, cautious descent towards the heavily armoured compound that surrounded the Took facility. ‘And I need you to be cold too, Mara, as we go through this day. Cold in the face of what you’re going to see.

‘Look down. This plant is typical of its kind. There is the torus, the heart of the exotic-matter facility itself. That rather ugly fenced-off area to the north is the workers’ compound. There are barrack blocks, refectories, stores, crude hospitals. A mortuary. You can see that the local supply canals have been hastily widened . . .

‘You must be prepared, Mara. You’ll be kept safe. But you asked about the use of criminals in such facilities. Mara, the Qax – or their human agents – use criminals as a police force, in the camps. You may imagine the quality of the resulting regime. You could argue we brought this on ourselves, with those foolish strikes from space. And there is another issue you must be prepared to deal with.’

‘What’s that?’

‘Juq. Your son, my nephew. In this region at least he has continued to serve as a public front for the project.’

‘I haven’t seen him for some days, but I do see his smiling face in news Virtuals.’

‘Smiling, yes. I think to the Qax and the Corps he serves as a symbol of authority over the workers. Look how your human superiors smile while you work yourselves to death in these hazardous places. You have no hope of help from them, or anybody else – no hope at all. That’s what Juq’s handsome smile has become: a symbol of the repression. You can imagine how the workers feel about that. He has to be heavily guarded.’

‘I can imagine. Though I don’t suppose Juq himself understands.’

‘He does not,’ Chael said heavily. ‘There was an incident last week, at the Wills plant. A clumsy worker, lining up for inspection, spilled a lubricant on the shoes of Juq’s friend, Tiel. Just an accident. Juq slapped her, and then laughed.’

‘He slapped her . . .’ Mara sighed. ‘That’s Juq. He was always that way with the servants. He never injured them, but—’

‘It is himself he has injured. You can imagine how the Virtual image of that act has permeated that facility, and others. He is becoming – hated. And, as you say, I’m quite sure he has no idea.’

Mara closed her eyes. ‘He’s not a fool, you know. He isn’t evil. Just flawed.’

‘Well, he’s your son. And he may need your protection . . . Almost down.’

The flitter descended to a crude concrete apron, hastily laid. Beyond security fences, before the backdrop of the giant torus, Mara glimpsed people, men, women and children dressed in identical green coveralls, gaunt and cowed. Most wouldn’t even meet her gaze.

She braced herself as she prepared to get out of the flitter.

6

As with every significant event in the human world – every event approved of by the Qax, at least – the Interface completion ceremony in Jovian orbit was saturated with coverage, with multiple sound feeds and images taken from every conceivable angle.

And so the assassination was covered in fine detail.

Mara, sitting in her home in Mellborn, forced herself to watch the sequence of events over and over, from as many angles as she could find. In the end, she discovered a feed from one observer who had been right on the shoulder of the anonymous Friend of Wigner, as she turned killer.

The ceremony, coming a mere month after the start-up of the new city-centre plants, had taken place aboard the lifedome of the Endurance itself. A small stage had been set up at the centre of the domed chamber, on which stood a number of senior officials from the project, both technical and from the Diplomatic Corps. But, to Mara’s eyes at least, the group was dominated by the unmistakable figure of her own son, Juq, tall, smiling as always, that blond hair blazing bright. His friend Tiel stood beside him, as he had since the beginning of this strange project, ever present, yet somehow as inconspicuous as a shadow.

Beyond the glimmering near-transparency of the dome over all their heads, Jupiter swam, an arc of that huge planet visible, a smear of golden brown. And, before the planet, rising into view like an angular dawn, the Interface portal – yet to be attached for the voyage – drifted towards the GUTship. Mara stared at the dazzling sky-blue of the portal’s exotic-matter icosahedral frame, letting her gaze linger on the cool edges, the geometrically perfect vertices that joined them. The faces were like semi-transparent panes of silvered glass, through which Mara could make out the watercolour clouds of Jupiter overlaid with a patina of silver-gold. And every few seconds a face would abruptly clear, just for a dazzling moment, and afford Mara a glimpse of another space, unfamiliar stars. Like a hole cut into the sky.

As the Interface passed over the dome, applause, apparently spontaneous, rippled. It was magnificent. It was beautiful. And humans had built this. Every time she gazed on this sequence of images it made Mara want to weep, and wonder if Chael had been right all along, if this monumental human achievement was worth whatever price would be exacted by the future.

Then officials on the stage began to speak, words Mara had already heard many times in her viewings. But the speeches were, for Mara on this recording, obscured by the muttering of the assassin, close to the automated camera-microphone that happened to be following her: The Wigner paradox is inescapable. The chains of unresolved quantum states will build on and on, growing like vines, extending into the future, until the observations of the final cosmos-spanning minds rest on aeons-thick layers of history, studded with the fossils of ancient events . . .

She was unprepossessing, Mara thought. Unremarkable, in a shabby green worker’s uniform of the kind that was common in Mellborn now, a young woman so sallow and fleshless it was hard to tell her age – perhaps twenty, not more than twenty-five. But her head was shaven. Even her eyebrows were gone, Mara saw. And now, as seen from the viewpoints of those around her, she began to move through the crowd, unremarked, towards the stage.

At last life will cover the universe, still building the regressing chains of quantum functions. Consciousness must exist as long as the cosmos itself – for without observation there can be no actualisation, no existence – and, further, consciousness must become coextensive with the cosmos, in order that all events may be observed. The chains of quantum functions will finally merge at the last boundary to the universe: at timelike infinity . . .

People were seeing her without watching her, Mara realised, dismissing her mad rambling, without thinking she was any kind of threat. Perhaps they saw no need to fear. Perhaps those admitted to this ceremony had already been screened for security. And perhaps a worker like this, mixed up, talking to herself, wasn’t a remarkable sight in the new, highly pressurised labour camps of the Qax.

But now, as she neared the stage – Mara glimpsed Juq up there still, golden hair shining, beneath the glorious vision of the Interface – the woman started to speak more loudly. Those around her looked perturbed, but still they did nothing to stop her.

At timelike infinity resides the Ultimate Observer. And then the last Observation will be made. Retrospectively the history of the universe will be actualised . . .

She was almost shouting now. People in the crowd were reacting at last, recoiling from her, and on the platform they were looking alarmed, pulling back – all save Juq, who stood there smiling down even on this disturbance.

And then Mara heard the ringing cry that haunted her dreams. Look out! She has a weapon!

The girl’s last words were almost a scream, as her arm lifted up straight before her, a heavy mass in her hand. Actualised in a history which maximises the potential of being! Which makes the cosmos through all of time into a shining place! A garden free of waste, pain and death!

Tiel threw himself forward.

From a hundred angles Mara had seen the boy’s chest explode, and the Wigner’s Friend pulled down at last, still screaming, and her son, still on the stage, still smiling even as he looked down, bewildered, at the splashes of his friend’s blood on his vest.

7

The Endurance was launched on schedule, hauling its massive wormhole Interface away into deep space at high accelerations, leaving the partner Interface patiently orbiting Jupiter. Even now nobody in Mara’s circle knew what the true purpose of the Qax Governor’s experiment had been – not even Chael, as far as she could tell, not even her beautiful idiot of a son.

But everybody knew the timescale from now on: the ship’s construction had taken six months, and in a mere six more months after its launch the Endurance would return, and a gate to an unknown future would open.

As the due date for that return approached, Mara waited tensely for whatever would come next. It was hard even to sleep without medication.

And then Chael called. He’d had a message from Jasoft Parz.

Chael hurried to Mara’s home in Mellborn. When he arrived Mara called Juq, and the three of them gathered in the cellar where once Juq and Tiel had run exotic-matter experiments with splinters of diamond.

The three of them sat in a circle, under a single light globe. It was only a year ago, Mara realised, that first meeting with Parz in this very cellar, and so much had come of it.

Chael now held up a sliver of inscribed matter. He said, ‘This was a one-shot, one-use message from Jasoft. He’s not been able to return to Earth since the Endurance was launched. I don’t know how he smuggled it out of the Qax ship where he’s being held. I brought it here for us to watch together . . . It may not be wise to attempt any recordings of it. Oh, and I brought this.’ He pulled a small plastic case from a pocket. Sealed within were three translucent tablets, each the size of a thumbnail. ‘These come from the Qax themselves. They are able to manipulate biochemical structures at the molecular level – did you know? That was their, umm, competitive edge when they first moved off their home planet. And this is the fruit of their study of mankind.’ He looked at them. ‘Do you know what this is?’

Mara could guess. The tablet meant the removal of death. ‘AntiSenescence treatment?’

‘Better than human-manufactured AS. A Qax refinement. They gave it to Jasoft. This is our reward, for our cooperation with the Endurance project. The former Governor kept his word that far.’

‘Former Governor . . .’

He handed them each a capsule. ‘Don’t take it yet.’

Mara nodded. ‘Let’s hear what Jasoft has to say first.’

Chael set the inscribed sliver on the floor. Immediately light flashed from the sliver, and pixels whirled in the air, quickly coalescing.

It was as if Jasoft Parz had joined the circle.

He sat at ease, in his usual expensive-looking robes. If anything he looked younger still, Mara thought, his face less lined, his colour healthier, those odd-looking black roots spreading under his hair. Yet he looked hunted; he glanced over his shoulder repeatedly as he spoke softly. ‘I don’t know how long I’ll be able to record. This message is my only chance. Please, all of you – listen and understand. Somebody needs to tell the human worlds what has happened – and what is to become of us.’

He allowed himself a grin. ‘First, the good news. Poole’s time bridge worked! As you’re aware, on the return of Poole’s ship Cauchy one group of rebels took the chance to go out and meet it – and they flew into the Interface, flew back through time, presumably all the way back to the age of Poole himself. We know now that the rebels were Friends of Wigner – the same ragamuffin group who attacked the Endurance when the Interface was completed, at Jupiter, and tried to assassinate Juq. And led, I’m told, by a young woman called Shira – she has links to the family of your son’s friend Tiel, I believe.’

Juq was wide-eyed at this. ‘Cousin Shira? I met her. But—’

Mara put her finger on his lips to hush him.

Parz went on, ‘Neither I nor the Qax Governor knows what the Friends intended, or indeed what they achieved, if anything. But their very actions threw the Governor into an existential panic, I think. Perhaps all the Qax could be wiped out, if humans were warned about the Occupation far enough into the past. The Governor proved surprisingly indecisive in the final crisis.

‘And thus the Governor chose to respond to Poole’s triumph by emulating it.

‘The Endurance was built to establish another wormhole tunnel to the future, from this age to around five hundred years hence. The Governor hoped to glimpse the Qax future, you see, and so be able to shape any decision with a kind of hindsight.

‘But what emerged from the wormhole, an emissary from the future, was not any kind of tactical guidance, but very bad news indeed – bad for the Qax, I mean, but we know few details. But, in the form of a new Governor for Earth – the former has been assassinated, by the way – it brought bad news for humanity too . . .’

Hastily Parz said that there would be a new phase of the Occupation, as the Qax strove to rectify their earlier leniency. It was to be called an Extirpation.

‘But I will not live to see this,’ Jasoft said now. ‘For the new Governor has a second string to the strategy. Even as Earth is smashed in the present day, the Poole wormhole to the past still exists. The Governor intends to drive Spline ships through the time bridge, and fall on the more innocent worlds of that historic era. And he intends to take me with him – into the past!’ He forced a smile. ‘In another life, another circumstance, what an adventure that would be. But as it is—’

The Virtual snapped out of existence.

Chael picked up the sliver, ran it over a slate for testing. ‘It’s done. Wiped.’

Mara said, ‘I wanted to tell him about his daughter, before he was lost in time. It would have comforted me, at least. Now he’ll never know. Perhaps we should find her, tell her of her legacy . . .’

Chael held up his own AS tablet. ‘We have more important decisions to make. Everything will be different now. We have no control over whatever Shira’s rebels do in the past, or what impact that may have – or what any Qax invasion fleet might accomplish. We, stranded here in this age, must deal with present and future. You heard Parz speak of the new regime to come, the Extirpation. But the Qax will still need humans to administer their regime for them. They will still need us. And the proof of it is in these tablets we hold. They want us to live on; they want us to work with them . . . We do have a choice, however,’ and he glanced around, almost as furtively as Parz had, Mara thought. ‘Callisto.’

‘What?’ Mara struggled to recall the name’s significance.

‘The moon of Jupiter?’ Juq asked eagerly.

‘Yes, the moon of Jupiter – and a hideout, for us. There’s a man called Reth Cana who, under cover of a science station, is providing refuge from the Qax regime – refuge for the likes of us. That’s one choice . . .’

Mara shook her head. ‘No. I’m no planetary traveller. This is my home, for better or worse. This is where I will live—’

‘And die?’ Chael said gently. ‘Well, that is another choice. We could simply see out our time and slip away – that’s if rebel assassins don’t hit us first. The final alternative is to live, on and on.’

‘In the service of the Qax? In which case we would face the same moral dilemmas we always have,’ Mara said. ‘By administering the cruelty of the new regime, perhaps we could find a way to alleviate it. But now there’s another reason to survive.’ Mara looked bleakly at her brother-in-law, at her son. ‘Some day the Qax Occupation will be lifted. And when humans run their world again, there will be a reckoning. A reckoning for us, and what we do next – what we have done already. You, Chael, for doing so much to assemble this Endurance project, to promote it. Myself for standing by when perhaps I could have stopped it.’ She touched her son’s hand. ‘And you, you foolish, silly boy.’

To Mara’s horror, Juq looked petulant, defiant, almost as if he might burst into tears. ‘But, Mother, it was wonderful. Such fun. It was glorious! Why, anybody would have . . . I meant no harm. You know me! I never meant anybody any harm.’

She pulled back. ‘You slapped a slave worker. Didn’t you? Perhaps that alone, that one moment, will be enough to condemn you.’ She weighed the tablet in her hand. ‘We have a duty to fulfil: to help our people through the dark times to come, and then, when the light returns, to stand trial for our crimes. Either way it is our duty to survive. Together, then.’

They took the tablets, Chael first, then Juq, and then Mara, and it was done.