They made a strange little procession, following a red-dirt path slashed across a meadow of black, close-woven, strap-like plants. Tony and the broker, Raqle Thornhilde, immense in a white kaftan and a wide-brimmed straw hat, the aquarium cylinder of the !Cha raised on its three legs, and three identical bodyguards in white shirts and black kilts. Raqle Thornhilde's weircat ran in swift loops and circles across the meadow, once jumping onto a prow of rock and raising itself on its long legs, silhouetted against the slow apocalypse of sunset.

'She can hear her prey hiding in their burrows,' Raqle said. 'She triangulates the heartbeat, then leaps high into the air and augers down into the dirt. So fierce. So precise.'

Tony didn't know what to say to that. He supposed that it was some kind of warning.

Now the biochine flung itself from the prow rock and sped out across the meadow again.

'I love to see her run,' Raqle said. 'I take her out of the city when I can, but never for long enough. I have too much to do, and many of the people with whom I do business find my sweetheart intimidating.'

'I find you intimidating, madam,' Tony said.

'Good. Perhaps you're not as stupid as you seem.'

Raqle had made it clear that his fate was subject to her whim. 'You didn't put up much of a struggle,' she had said, back in the little prison shack. 'I think you wanted to be caught.'

'I wanted to talk to you,' Tony said.

'It was almost clever, luring me to approach you by advertising yourself about town, but it attracted the wrong kind of attention. That's why I had you brought here. It was for your own good.'

'People keep telling me that,' Tony said, thinking of Ayo and Opeyemi.

Raqle said that she had not questioned him until now because she had been waiting for the !Cha to arrive. The alien would be able to detect the slightest deviation from complete truthfulness and sincerity, she told Tony, and warned him that any hint of duplicity would be severely punished.

Tony said that there was no need to threaten him because he would be happy to talk about why he had come back to Dry Salvages. He told the broker and the !Cha about his adventure on the slime planet, and how the wizards had discovered the Ghajar algorithm in the stromatolites and accidentally freed the eidolon. He described the raid on his family's home and its aftermath, explained that he had escaped and set out to find Aunty Jael.

He did not mention Colonel X, hoping that Raqle Thornhilde and her !Cha would not be able to sniff out the lie of omission. The broker was a formidable person, sly and dangerous, and he was at her mercy. But he needed Colonel X as a hole card. He wasn't hoping for rescue, but it was always useful to have something in reserve.

She did not tell him whether she believed his story; nor did she tell him whether or not she had been involved with Aunty Jael's escape. Now, as they walked towards the compound where the children were kept, he was waiting on her judgement.

'Look at her run!' she said. She was still watching the weircat. 'I love her purity. She is a killing machine. Fast and sleek and unforgiving. She feels no remorse when she brings down her prey. And you cannot plead with her, if she targets you. She is what she is. She does not care that she was designed by unknown minds and hands. She is what she is. She does not meddle in things she doesn't understand, or dream that she can become other than she already is. If we were a little more like her and all the other biochines, if we weren't so restless, so stupidly inquisitive, then perhaps we might not be afflicted by meme plagues or possessed by eidolons. We might not have scattered ourselves so widely and thinly, or warred against each other over stupid little differences. We might not be trembling on the edge of extinction.'

'But you would be a great deal less interesting,' the !Cha said.

It was still startling to hear his rich baritone, to remember that his tank was not a drone but a kind of spacesuit for a little colony of smart shrimp.

Tony had never met a !Cha before, although he had once glimpsed one on a city street on a world thirty thousand light years away. Their relationship with the Jackaroo was unclear, but they freely admitted that they were connoisseurs and collectors of human stories, and many believed that they manipulated people and events to make those stories more interesting. This one's name was Unlikely Worlds. Tony supposed that he was following Raqle's story, her life; supposed he would become a small part of that tale. It was not a comforting thought.

'You are biased,' Raqle told the !Cha. 'You like us to burn brightly and briefly because that creates interesting stories, and interesting stories turn on your females.'

'You would create stories anyway,' Unlikely Worlds said. 'It is in your nature to elaborate worlds that do not exist.'

'The point is,' Raqle said, 'we'd live a lot longer if we didn't meddle in things we don't understand. We wouldn't be divided as we are. Our children wouldn't be dying of sleepy sickness.'

'And you would not aspire to glory and godhood,' the !Cha said. 'I do envy you that. And not just because it makes such good stories.'

'No doubt you said that to all the Elder Cultures. And look at them. Like Ozymandias, one and all.'

'I am old, certainly. But not that old.'

'So you'd like me to think. Oh, just look at her!' Raqle said, turning from Unlikely Worlds to look across the meadow again. 'Such speed. Such fierce joy. Now there's something to envy!'

'I'm not so sure,' the !Cha said. 'Weircats are found only on Dry Salvages and two other worlds. And on all three they are scarcely numerous. Each needs a territory of several hundred square kilometres, in the right kind of desert. Made or evolved, they have specialised themselves almost out of existence.'

'Three worlds that we know of,' Raqle said. 'There are thousands we haven't yet touched. And besides, because of us, because we have taken them with us, they live on more than three of the known worlds now. After we die out, the Jackaroo will find new clients, and perhaps they will wonder why certain species are always associated with the ruins of our cities. Perhaps that will be our only legacy.'

'We will remember you,' the !Cha said.

'You collect our stories and turn them into love feasts for your females. What about Mr Okoye? How does his story taste to you?'

'It tastes of truth,' Unlikely Worlds said.

Tony felt a wash of relief, and realised at that moment exactly how anxious he had been.

'That's what I thought,' Raqle said. 'He didn't tell me much that I didn't already know, but it's clear now that I've been played for a fool. And by a laminated brain, of all things.'

'If it's any consolation, she has been playing the game a lot longer than you,' Unlikely Worlds said. 'This is a new chapter in a long and enthralling tale.'

'His story isn't worth much by itself,' Raqle Thornhilde said. 'But I think you'll agree that it definitely adds something to hers.'

'Oh, I think it's safe to say that I haven't been disappointed,' Unlikely Worlds said, and Tony realised with a little thrill of hope that the !Cha was not interested in his story, or Raqle Thornhilde's, but in Ada Morange's. That there was a chance he could turn that interest to his own advantage.

'Then you'll give me your help,' Raqle said.

'We will help each other,' Unlikely Worlds said.

'Yes, we will,' Raqle said, and took out a small golden cylinder and put it to her lips and blew. Tony did not hear anything, but out in the meadow the weircat turned sharply and ran headlong towards them.

They walked on to the place where the children infected with sleepy sickness were kept. A plastic mesh fence strung on concrete posts with three strands of barbed wire stretched along its top; a dusty compound; a long windowless barracks built of the same sandstone blocks as the huts of the real free people.

'It isn't much compared with the clinic run by your family,' Raqle Thornhilde told Tony. 'Pyotr's people do what they can, but there are no trained medical personnel, no hands or drones, no attempts at remedial treatment, no wizards trying to find a cure. But the children have food and water and shelter. They are free to do what they need to do. What their disease needs them to do.'

There were about twenty children beyond the fence. A small group huddled around something Tony couldn't see, but most stood or sat by themselves. Several were staring at the sunset. A tall blonde girl, hands knotted at her chest, sang over and over: 'La! La-la-la. La!'

Raqle Thornhilde stepped closer to the fence, hooking her fingers in its diamond mesh, gazing at the children with fierce tenderness. 'My son died here,' she said. 'He began to show symptoms just after his eleventh birthday. I brought him here, and he died two years later. The kind of medical intervention your family provides can keep them alive for longer, but what's the point? During the first stage of infection, the meme eats their minds while they sleep. When they wake, they are no longer what they once were. They are not even children.'

She spoke flatly, without affect. Tony supposed that it was the only way she could bear to talk about it.

'I cloned my son,' she said, 'but of course it isn't the same. I knew that, even at the nadir of my grief. His siblings may look like him, they share his genome, but I had them tweaked to be stupid and loyal. I wanted him to live, but I couldn't stand the thought of another person wearing his body. Of living the life he had lost. Of living a life different to the life he would have had. He was one of the first, twenty years ago. How it's spread since then! I have not been able to change the quarantine law. I have not been able to stop people turning them out of the city. So I pay the real free people to round up as many as they can, and look after them here.

'That was why I was interested in the stromatolites. I believed the story that there might be a cure hidden in their archival genetics. And you and your family wanted to believe it too.' Raqle Thornhilde turned to look at Tony. She was dry-eyed, quite calm. 'I had nothing to do with what happened afterwards. I thought that your Aunty Jael could help to find a cure. I didn't know who she really was.'

'My family and I were fooled too,' Tony said.

'A pleasing symmetry,' Unlikely Worlds said.

Raqle Thornhilde ignored the !Cha, telling Tony, 'You came to me because you thought I'd helped her to escape. I didn't. But I want to find her, as do you. And we're going to help each other. I'm not doing this to get some sort of revenge, or so this fucking school of shrimp can get his rocks off. I want to find out if there's any truth to the idea that there's a cure for sleepy sickness out there. I'm doing it for the children. As far as I'm concerned, it has always been about the children.'

37. 'I can see ghosts.'

Unlikely Worlds was the!Cha Chloe Millar had warned Lisa about, the one who was making a story out of Ada Morange's life. He said that he had come to First Foot because he believed that what he called Lisa's accident was about to become an important part of that story. A story that was, according to him, a great work of time.

'And it is not yet even halfway done. She changed human history with the discovery of the Ghajar ships, and now she may change it again. This time with your help, Ms Dawes, and the help of the eidolon in your head, so recently embiggened.'

Lisa said, 'How do you know it's been . . . What was it you said?'

'Embiggened. A cultural reference. A small joke. Perhaps too obscure? Oh well. We try to please and sometimes we try too hard. As for your eidolon, I can see ghosts. Although perhaps not in quite the same way that you see them. How did it happen, may I ask?'

'Isabelle didn't tell you?'

'I prefer to hear these things first-hand,' Unlikely Worlds said.

His mellifluous baritone sounded like the dead guy who did the voice-overs for the kind of movie trailers that were full of explosions and military hardware and collapsing megastructures, and who was now a kind of ghost himself, an AI that perfectly imitated him. Lisa and Isabelle were sitting on a flat slab of rock in the shade of the organ trees; Unlikely Worlds had folded his three skinny multi-jointed legs to squat in front of them. The flat-topped cylinder of his tank was about a metre tall, matt black and textured with a fine grain, like expensive hand-made paper. He wasn't the first !Cha that Lisa had met. There had been another, Useless Beauty, sniffing around her and Willie after the Bad Trip. Lisa, unsure of the !Cha's authority, had told him what she remembered of the incident; Willie claimed to have strung him along with the promise of some grand tall tales. Hoping for payment that had never come. Useless Beauty had listened to them and had not returned; they had never learned if he had been satisfied with their stories or if he had found them wanting, or why. And now here was this one, wanting more of the same. Even without Chloe's warning, Lisa wouldn't have trusted him, but Isabelle Linder didn't seem to be fazed by his presence, telling her, 'He'll get it out of you one way or another. So you might as well tell him now.'

So for the second time that morning Lisa explained what she had felt at the moment of Willie's death. It was like hearing someone else tell a story. When she was done, there was a long moment of silence broken only by the fluting of the hot breeze in the hollow tops of the organ trees.

'Such a rare encounter,' Unlikely Worlds said at last. 'The Ghajar were once more numerous than you, but they hardly ever visited the worlds they had been given. They were a little like your gypsies, and a little like poet-warriors in the classic sense. They left behind their ships, but almost nothing of themselves.'

Lisa said, 'Is my eidolon the ghost of a Ghajar?'

She wanted to ask: if you see it what does it look like? Can you talk to it? How has it been changed? What does it want? Half a hundred questions were buzzing in her head.

'It is definitely interesting,' Unlikely Worlds said.

'In what way?'

'In the way its story crosses with yours, and yours crosses with Ada Morange's. In the way the deep past is reborn in you. In the way it manipulates the future in which it finds itself. How to tell a story? First find a point of view. But this has so many perspectives. It is quite deliciously dizzying.'

'There is no point asking him for actual answers,' Isabelle said. 'He finds it amusing to answer questions with riddles.'

'Or quotes from movies,' Lisa said.

'Yes, that also. He is very tricky.'

The two of them exchanged conspiratorial looks, as if talking about a gifted but wayward child instead of an alien entity that inhabited a walking aquarium.

'I have no wish to violate the prime directive,' Unlikely Worlds said. 'It would make things so much less interesting for all of us if you were not able to discover your own destiny.'

Isabelle said, 'I have always wondered about this delicacy concerning interference. Is it your idea, or the Jackaroo's?'

'You try to discover if we are their servants. Or if we are an aspect of them. It's true that our very different scruples and intentions sometimes appear to have similar outcomes, but otherwise we have little in common.'

Although the !Cha claimed to be a separate species and implied that they and the Jackaroo were coevals, no one really knew if they were servants, secret masters, mere hitchhikers, or another manifestation of the Jackaroo themselves, another form of avatar. They also claimed that they were schools of tiny fish or shrimp or things a little like fish or shrimp that possessed a collective consciousness, and there was no way to prove or disprove it because their sturdy mobile aquaria were impervious to microwaves, X-rays, ultrasound and every other kind of probe.

'We like to help,' was all the Jackaroo said, when asked about the !Cha. It was their stock answer to most questions.

There weren't many !Cha. A hundred or so, all of them male. According to them, they travelled about Earth and the gift worlds collecting stories they hoped to use to woo their sedentary females. This one, Unlikely Worlds, had contacted Isabelle two days ago, requesting a lift on the ship sent by Ada Morange. Before that, Isabelle said, she'd had no idea the !Cha was on First Foot.

'I think he thinks the breakout is very important,' she'd told Lisa. 'But he refuses to tell me exactly why.'

'Perhaps I don't yet know because the story's far from done,' Unlikely Worlds said now. 'But I do admit to an interest in Ms Dawes. I look forward to finding out what Ada makes of her pair bond.'

'You mean me and Willie?' Lisa said.

'I do not refer to your marriage,' Unlikely Worlds said.

'I don't have any kind of relationship with my ghost. It's a parasite. An infection.'

'Yet you seek a divorce.'

'I'm looking for a cure,' Lisa said. 'If you're interested in my story, you should get the basics right.'

'There is a problem,' Isabelle told the !Cha. 'Before we go to the place where the ship will pick us up, Lisa wants to visit the excavation site. I tell her it is dangerous, but she will not listen.'

'I want to see it for myself,' Lisa said. 'It's why I came out here in the first place.'

She hoped that it might somehow jog her memory, help her understand what had happened to her during the Bad Trip. And she was wondering if there might be other Ghajar fragments close by, overlooked by the Outland crew and the geek police. Something she could use to win a better deal with Ada Morange, or to bargain her way out of her jam with Adam Nevers and the geek police. Something that could be used to get the eidolon off her back.

'It isn't a problem at all,' Unlikely Worlds told Isabelle. 'In fact, it's a wonderful idea. Who knows what Ms Dawes might see, with the help of her ghost!'

Isabelle drove at reckless speed across the salt pan, heading back to the hills and the overlook that her tomb-raider guide had shown her. Lisa was buckled into the passenger seat; Unlikely Worlds perched behind the gap in the front seats. They followed a draw that climbed in winding curves between steep bluffs, turning north when it topped out, skirting the foot of a fluted cliff before descending a scree slope into a narrow valley. A dead spot, according to Isabelle.

They sheeted the Land Cruiser in camo cloth and hiked up a dry stream bed that wound between slopes of tumbled stones. Isabelle set a challenging pace. Unlikely Worlds quickly fell behind, but when Isabelle and Lisa scrambled up a long steep slope they found him waiting for them at the top, beside a short string of Boxbuilder ruins that ran along one edge of a flat triangle of bare rock. Lisa saw a faint movement inside one of the grainily translucent cubes, like a swirl of cigarette smoke captured in a video loop.

'He does that,' Isabelle said. Meaning, Lisa realised, the !Cha.

The young woman, scarcely out of breath, had a healthy glow from the hike. Lisa was slick with sweat and puffing like an old steam engine, and a knife prised at her left knee with every other step. The view was worth it, though. The view was magnificent.

The triangular prow of rock dropped straight down on two sides. To the west, the white sands of the Badlands stretched to the horizon and the setting sun. To the east, the range of hills and bluffs rose above slopes creased with deep shadows. And a fleet of flat-topped buttes dwindled away directly ahead, glowing in the sunset like the magic-hour master shot of a John Ford Western. Lisa saw something glittering at the top of a distant butte like a diamond refracting laser light.

The excavation site was at the base of the nearest butte, two or three kilometres away. Through the powerful field glasses that Isabelle lent her Lisa saw a dozen powder-blue trucks and Range Rovers parked at the edge of the conical piles of talus in which the butte's rugged column was rooted. A yellow digger and the ribbed half-cylinder of a big tent stood on a setback halfway up a steep slope. Lisa saw someone walk out of the tent, stalking ahead of their long shadow, saw other people sorting through debris laid out in neat squares. She saw a golden glint, realised with a cold start that one of those tiny figures was a Jackaroo avatar. And she saw a pit and a tall spoil heap which must be the entrance to the Ghostkeeper tomb. The refuge of the Ghajar survivor of the spaceship crash. The place where the Outland crew had murdered each other after they'd been possessed by bad code.

Unlikely Worlds asked her what she saw.

'The tomb's entrance. People. Also a Jackaroo avatar. They're pretty close to the tomb, those people. I thought it was still dangerous.'

'Yes, but what do you see? What is there beyond the trivial activity?'

It took Lisa a moment to realise what he meant.

'I can't see anything. No ghost lights. Either I'm too far away, or the geek police and their Jackaroo pals found some way of neutralising whatever it was Willie and the others found in there.'

'For what it is worth, I cannot see anything either,' Unlikely Worlds said.