The ship punched out of the atmosphere, fired off a package of tiny cube satellites, and continued to rise. The horizon rounded and the dull spark of the slime world's solitary moon rose above it, a skull-shaped chunk of rock fifty kilometres across, with an erratic retrograde orbit. Fred Firat had believed that it was an asteroid that had been moved into orbit by some Elder Culture for some unclear purpose; deep radar scans had revealed that it was riddled with tunnels, including a shaft that pierced it through its rotation axis.

After Abalunam's Pride matched the little moon's orbital velocity, Tony took control for the final manoeuvre. Blipping the ship's drive, setting her on a trajectory that would intersect with the moon's surface. This was the fun part. The target area was relatively small, and there was only a narrow window before the frigate appeared over the horizon of the slime planet.

The moon swiftly grew, its lumpy cratered landscape raked with fault-line scarps. Abalunam's Pride swung around it, dawdling towards the flat top of a debris cone: the north polar entrance to the shaft that pierced the moon, created by unimaginable energies that had vaporised fifty kilometres of rock. Much of that vapour had boiled away, escaping the grip of the moon's feeble gravity; a small fraction, cooling, had fallen back to the surface and formed symmetrical cones at the poles.

Tony mirrored the visual feed to his passengers so that they could watch some real piloting skill, killed the last of the ship's forward momentum as the cone's flat top slid past, and dropped into the black circle of the shaft's entrance. He fired off a package that would anchor itself to the shaft's lip and allow him to keep in touch with the cube sats, and then Abalunam's Pride was falling between smooth melt-rock walls, slowing, slowing, until it was floating freely at the midpoint of the shaft, balanced at the null point of the asteroid's feeble gravity.

'We will wait here until the frigate puts down,' he explained over the common channel. 'And when it does, we'll make a run for the mirror.'

He had to wait almost twelve hours, half a day in old money, while the G-class frigate swung around the slime planet in a near-polar orbit that would enable it to scan almost every part of the surface. No doubt they had checked out the little moon, too, but Tony was pretty sure that his hiding place was safe. Radar scans could render the moon transparent, but their resolution was limited. The claim jumpers would not see his ship until he wanted to be seen.

At last, the frigate fell out of orbit in a smooth trajectory aimed at the lone continent. Tony told his passengers to brace themselves, and exactly a hundred seconds later booted the ship. Maximum acceleration. The walls flashed past; a star of sunlight flared ahead and widened into a perfect circle; Abalunam's Pride shot out of the shaft like a cannonball, still accelerating. The moon dwindled astern, and the slime planet dwindled too, rounding into a half-globe that shrank into the big dark like a pebble dropped down a well.

The frigate sent an interrogatory message. Tony ignored it. He was back in control, back on track. All he had to do now was reach the mirror.

It orbited the L5 point where the slime planet's gravity balanced that of its star. Tony flew a flat geodesic trajectory, accelerating all the way. This was the part he loved. He was cradled in his command couch, ramped up on combat drugs and plugged into the ship's bridle and her radar, EM and optical feeds. Flying free into the unknown. Master of his own fate.

He was more than halfway there when the feeds from the cube sats he'd left in orbit around the planet went dark. No problem. He had been half-expecting it after the claim jumpers' frigate had pinged him. But as he closed in on the mirror the assets that had been keeping watch on it went dark too.

It was the usual rock sculpted into a long cone, with the wormhole throat embedded in its flat base: a round dark mirror two kilometres across, framed by the chunky braid of strange matter that kept it open. The only mirror in orbit around this star. The only way in, the only way out. When he had come through, Tony had dropped off a package of drones that had established wide triangular orbits around it. They had not detected anything sown by the frigate, but it had set traps all the same.

Abalunam's Pride was briefly painted by radar and launchers planted around the mirror's rim flung a cloud of disrupter needles: electronic countermeasures packaged in little blades of cubic carbon allotropes denser than diamond, designed to lodge in the hulls of Ghajar ships and paralyse their nervous systems. There was no time for any kind of evasive manoeuvre. Tony shot a drone carrying a totally illegal pinch-fusion bomb with a yield of point six kilotonnes from Abalunam's Pride's launch cannon. Ayo had given it to him just before he'd set out two years ago, telling him that it had been held back when the family's armoury had been stripped by the Commons police, and was to be used only as a final measure in extreme circumstances. Well, if this didn't count as an extreme circumstance he didn't know what did. The bomb detonated scant seconds after launch, obliterating the needles in a furious fireball, and Tony screamed in triumph and blind terror as the ship slammed through the expanding shell of superhot plasma, plunged into the mirror of the wormhole throat, and emerged eight thousand light years away.

5. Breakout.

The next day, Lisa met up with Bria in Port of Plenty and downloaded everything she knew. Everything that Sheriff Bird and the boss of the geek police team, Adam Nevers, had told her. It wasn't much. It was heartbreaking.

It seemed that Willie had found something out in the Badlands, something too big to dig out on his own. He'd partnered up with a crew and they'd uncovered a powerfully malignant artefact that had got inside their heads and turned them against each other. Five people were dead; three, including Willie, were missing, believed to be buried under tons of rubble at the bottom of the excavation shaft after someone had blown it in, possibly in a futile attempt to contain the breakout.

'Do you remember the thing in Bitter Springs, two years ago?' Lisa said to Bria. 'The police said it was like that.'

A prospector had brought an artefact into the little desert settlement of Bitter Springs, the local assayer had woken the eidolon inside it, and there'd been a breakout and a massacre. People attacking each other with teeth and nails and fists and feet. Neighbours and strangers. Husbands and wives. Mothers and children. Lisa had seen the artefact in the Port of Plenty museum after it had been purged of every trace of its algorithms. A smooth slim black needle about the size of a spearhead, gleaming and sterile in its glass case. A reminder of the awful unknowns yet to be unearthed.

'Now I know what caused that seizure,' Lisa said. 'It was the same day the breakout happened. No way is that a coincidence. No. Fucking. Way.'

Bria reached across the little table and gripped her hands. 'Oh, Lisa.'

They were sitting outside the big Starbucks that anchored the western end of Pioneer Square. Lisa was drinking iced tea sweetened with half a dozen packets of sugar, Bria a flat white. Pete sprawled under the table with a dish of water. All around, people sat at cafe tables in the late-afternoon sunlight, perched on broad steps that dropped to the well where a gout of water pulsed and plashed. Smart little yellow trams ran along one side of the square, which was bordered by office buildings and the plate-glass windows of high-end shops. A sliver of Earth jammed into this alien world, where a dozen or more Elder Cultures had lived and died out or ascended to some unfathomable stage of consciousness, leaving behind ruins and artefacts, scraps of technology, algorithms and eidolons. A perfectly ordinary scene that, distorted by Lisa's blind spot and the intimate presence of her ghost, seemed weirdly unfamiliar, like a hyper-real simulation where everything was a banal, idealised version of itself and nothing fit together properly.

'Willie finally went and did it,' Lisa said, squeezing Bria's hands. 'After all this time, he finally found the thing that zapped us. It zapped him again, zapped the people he was working with. And it reached out to me. It woke the ghost in my head.'

'What did he find?' Bria said.

'The geek police wouldn't tell me. They think I already know. They think I'm involved.'

'But you aren't.'

'Of course not!'

Pete lifted his head, looking up at Lisa. She let go of Bria's hands and pushed her hair out of her face, the frizz of grey corkscrew curls she'd stopped dyeing a couple of years ago. She was bone-tired, had spent most of the night looking at the ceiling of her bedroom, her head like a beehive.

'I haven't seen him for three months,' she said. 'I had no idea what he was into.'

'And you told the police that.'

'It didn't make any difference.'

Lisa told Bria about the man who'd led the raid on her property. Investigator Adam Nevers of the UN Technology Control Unit: a tall Englishman with a neatly trimmed salt-and-pepper beard, dressed in a cream linen suit, light blue shirt and dark blue tie, polished brown brogues powdered with the red dust of her yard. He'd been very polite, very proper, but there had been a coldness in his manner, an Olympian condescension, as he explained that the search-and-seizure warrant had been issued because it was possible that Willie might have sent Lisa something potentially dangerous, or left behind something she believed to be harmless but actually wasn't.

'I think I'd know if he had,' Lisa said. 'It's kind of how I earn my living.'

'When you last saw him, did he tell you that he had found something in the Badlands?' Nevers said.

'Not a word.'

'Did he tell you he was going out there with a crew to dig something up?'

'I'd definitely remember that because Willie always worked alone.'

'Did you notice anything strange in his manner or behaviour?'

'No. He was just himself.'

'"He was just himself."' Nevers frosted the words with disdain. 'Exactly what do you mean by that?'

'Exactly what I said. He turned up one day, we caught up on what each other had been doing, and after a couple of hours he left.'

'So it was purely a social visit.'

'As far as I was concerned.'

It was hard to think of Willie, hard not to. Lisa saw his smile, his gold tooth flashing. The deep lines around his eyes. His black hair brushed back and held by a bandana folded just so. The warmth of him, his sour-sweet smell. They hadn't slept together the last time he'd stopped by because Lisa had been irritated by his presumption and they'd fallen into the groove of one of their old arguments. His selfishness; her stubbornness. She hoped that she wasn't going to have cause to regret the way they'd parted, that last time. She hoped that Willie had managed to escape unharmed, that maybe he hadn't been there when the trouble had kicked off. And then she thought of her seizure, and knew, with numb certainty, that he must have been caught up in it.

Nevers led her through the banal details of their last conversation, then threw her a curve ball, saying, 'Could your husband have visited your property without your knowledge?'

'I guess. I mean, I'm not here all the time.'

'So he could have left something here. Hidden it.'

'What kind of something?' Lisa was beginning to feel uneasy, because it was exactly the kind of stupid stunt that Willie liked to pull. Had liked. Jesus.

'That's what we want to find out,' Nevers said.

The other agents, two men and a woman, were walking in and out of the lean-to workshop tacked onto the end of Lisa's house, carrying away equipment and stacking it inside the two Range Rovers. Her ultrasound probe, her binocular microscope, the compact oven of her printer, her Reynolds trap . . .

The gold-skinned Jackaroo avatar stood between the vehicles, still as a statue. It had helped Adam Nevers perform a preliminary survey of the house and barn while Lisa sat with Sheriff Bird in his patrol car, trying to stay calm because she knew that if she lost her cool they'd definitely arrest her. She was still trying to stay calm, but it was getting harder while she watched her livelihood being ransacked and Nevers treated her like someone who was either incredibly naive or incredibly dumb. When she saw one of the men wheel out the tall black box of her massively parallel computer on a hand truck, she started towards him, saying indignantly, 'You can't take that!'

Nevers caught her arm, gripping so hard she could feel his fingers pressing on the bone. He said, 'You'll be given an inventory of everything we take. And if there isn't a problem it will be returned to you as soon as possible.'

Lisa watched, heartsick, as the man wrestled the computer into one of the Range Rovers. Everything its hard drive contained was deeply encrypted, she wasn't about to hand over the keys unless compelled by a court order, and she had a backup that the police hadn't yet found, but she'd built the machine herself and she couldn't afford to replace it.

Nevers said, 'I understand that you were a hotshot coder back in the day. You worked out how to crack Ghostkeeper algorithms, and gave away the method.'

'It was a kernel defining an environment where people can run the algorithms. And I put it out under a Creative Commons licence. Not quite the same thing as giving it away.'

'But you didn't make any money off it, while other people did,' Nevers said.

No point trying to explain to the man that she'd been part of a collective, that she'd just happened to have had the crucial insight that helped move forward a communal effort, that everything back then had been different, more hopeful, not yet thoroughly tainted by commercial interest and the social Darwinism of neoliberal capitalism. Nevers clearly had marked her down as some kind of eccentric hippie who'd not only been fucked up by an alien ghost, but had also squandered her intellectual property out of misplaced idealism.

She said, 'You can let go of my arm. I'm not going to try to stop your people doing their work. Even if it is legalised theft.'

'We're dealing with a serious breakout, Ms Dawes,' Nevers said blandly, releasing her. 'We'll return your equipment after we've examined it. As long as it isn't contaminated, that is.'

Lisa resisted the urge to rub her arm. It felt like the man had left a bruise the size of Nebraska. 'My containment protocols are as good as anyone else's.'

'Then there shouldn't be a problem,' Nevers said, and handed her a business card. 'If you remember anything that might help us find out what happened to your husband and his friends, don't hesitate to get in touch.'

'So are business cards still a thing, back on Earth?'

'I'm no newbie, Ms Dawes. If that's what you're trying to imply. I've been working on cases like this for a very long time. Longer than you've been working on Elder Culture code, I dare say.'

'Well you don't appear to have learned very much,' Lisa said.

That bounced right off Nevers. He said, 'I saw the funny tortoise-things you have in the barn. Is that how you make your living now?'

'The hurklins? Yeah, I ranch them.'

'For meat?'

'You can't eat them. They have funny amino acids, use vanadium in their blood . . . What it is, they shed the outer layer of their shells as they grow. It's like very fine-grained leather, naturally tinted.'

She thought of Willie again, his ancient leather jacket, his cowboy boots with their silver tips and conchos. Oh, Willie.

Nevers was saying something about having had a tortoise as a pet when he was a kid. 'An age ago, in London. I painted the shell once, my idea of dazzle camouflage. But I wouldn't have thought to try to wear it.'

It was hard to imagine him as anything other than what he was, tall and straight-backed in his cream suit, radiating the stern rectitude of an old-time preacher. His flinty probing gaze, his shuttered expression. One of the agents came over with a tablet that displayed an inventory of the things they'd taken. Lisa studied it carefully before she signed it.

'We'll email you a copy,' Nevers said. 'Oh, one more thing. Your phone.'

'My phone?'

'Please,' Nevers said, holding out his hand.

Lisa thought of arguing, but knew that if she refused the agent would grab hold of her and Nevers would pat her down. She took out it out and said, 'Make sure you add it to your inventory.'

'Thank you for your cooperation, Ms Dawes,' Nevers said. 'If we have any more questions, we'll be in touch.'

She barely heard him. She was watching the Jackaroo avatar approach. Its elegant dancer's walk, as if gravity were optional. Its immaculate black tracksuit. Its gold-tinted face, eyes masked by sunglasses exact copies of Ray-Ban Wayfarers. Jackaroo avatars presented as male, composites of fashion models and movie stars, but their gender was as superficial as a mannequin's, and more than thirty years after First Contact they were still unfathomable enigmas.

Humanity had been hard-pressed back then. Countries fighting over dwindling natural resources; riots, revolutions and counter-revolutions, and the constant low-level attrition of netwars; a billion refugees made homeless by famine, flood or extreme weather events. All of this craziness culminating in the Spasm, when more than a dozen capital cities from London to Karachi had been damaged or destroyed by low-yield tactical atomic bombs and a limited nuclear missile exchange.

The Jackaroo had arrived a year later. They brought with them fifteen wormhole mouths and fifteen colossal shuttles, infiltrated the world's communication networks, and declared that they were here to help. The wormhole mouths led to habitable worlds orbiting red dwarf stars smaller and cooler than Earth's sun, the most common type of star in the galaxy scattered across the Milky Way; winners of the UN emigration lottery travelled up and out on the shuttles, hoping to begin new lives in these new worlds, which turned out not to be so new after all. Previous clients of the Jackaroo, the so-called Elder Cultures, had colonised the worlds and altered them in various ways before either dying out or moving elsewhere, leaving behind ancient ruins and artefacts.

No one knew what the Jackaroo actually looked like, where they had come from, or why. They presented only as avatars, no one had ever visited their ships, and they wouldn't ever discuss their motives, what had happened to the Elder Cultures, what might happen to the human race. We're here to help was all they said. Every client's path is different. Lisa, who'd been in high school back then, remembered the wave of optimism that had swept across the world after First Contact. Humanity was no longer alone in the universe. The Jackaroo were benevolent ambassadors of an advanced culture whose gifts promised the kind of utopian future, packed with miracles and marvels, that had long seemed for ever out of reach. Mining Elder Culture ruins had yielded room-temperature superconductors, construction coral, self-healing plastics and new meta-materials, entangled pairs of electrons that allowed instantaneous transmission of information across interstellar gulfs, and much else. And then there was the discovery of ships abandoned in orbital sargassos by the Ghajar, and the wormhole network of the New Frontier . . .

Lisa had bought into that dream when she'd won a lottery ticket and come up and out, but she knew all about its dark side now. The Bad Trip, possession by an ancient alien ghost, addiction to a drug distilled from an alien plant . . . And she'd had a close encounter with a Jackaroo avatar once before, in hospital soon after the Bad Trip, when she'd told her story and had been left feeling that she'd been judged by some higher being and found wanting.

So she clenched up as the avatar, maybe the one that had interviewed her back then, maybe a colleague, impossible to tell, walked towards her. It held out a hand, palm up. A small sharp-edged stone lay there, black against translucent golden skin. After a blank moment, Lisa realised that it was her only tangible souvenir of the Bad Trip.

'Remember the stone you helped me test for activity all those years back?' she told Bria. 'That one. I must have picked it up before Willie and I were zapped, and found it in the pocket of my jeans a month later.'

Lisa had hoped that it might contain some clue about what had happened to her and Willie out in the Badlands, but it had turned out to be just a rock. A little chunk of chromite, commonly found where erosion exposed the igneous rocks that underlaid the sandstone of the Badlands; an unknown Elder Culture had mined seams of chromite ore in the far south, leaving huge terraced sinkholes.

She said, 'I kept it in a bowl in the living room, with a bunch of pebbles and spent tesserae. Souvenirs of the places Willie and I excavated. I guess the tesserae pinged the avatar's radar you know how they can track down stuff like that. And when it found them it also found the little black stone, and wanted to know what I knew about it.'

'What did you say?'

'That it came from someplace I couldn't recall out in the Badlands,' Lisa said, remembering the avatar's blank scrutiny and pleasant smile as it asked her if the stone had ever manifested any kind of activity. Although it was a shell of gold-tinted translucent polymer, remotely controlled by God-knew-what, God-knew-where, its face was mobile, disturbingly alive, disturbingly almost-but-not-quite human.

'Of course not. It's just a stone,' Lisa told it.

'Nevertheless, I must keep this for now,' the avatar said, and closed its fingers around the stone and walked away, while Nevers reminded her to call him if she had any questions or remembered anything germane.

'First time I've ever heard someone use the word in cold blood,' Lisa told Bria. '"Germane."'

Bria said, 'He didn't charge you, threaten to charge you?'

'He didn't need to. He confiscated my shit, and sooner or later he'll offer to give it back if I tell him what I know about Willie's jackpot. And the thing is, while I don't know anything but what Sheriff Bell told me, I'm definitely tangled up in it.'

'Because of your seizure.'

'Exactly. Listen, I was sort of wondering if you could maybe do me a favour or three.'

'You only have to ask, honey.'

'First, I have a feeling I might need a lawyer.'

'Of course. I have a good man on retainer.'

'The second thing, I thought I'd ask around in the Alien Market, tap into any gossip about Willie's jackpot. And while I'm doing that, maybe you could find out if he did the right thing for once in his life, and registered a claim.'

'Is that all? It doesn't seem like much.'