Lisa changed the subject, asked about the Jackaroo avatars. Were they working for the TCU, or was the TCU working for them?

'They are here to help.'

'Yeah? So why aren't they helping Ada Morange?'

'Perhaps they are, in their own way.'

'From my limited perspective and experience, I'd say they don't want her to find what she wants to find,' Lisa said.

'Investigator Nevers certainly does not,' Unlikely Worlds said. 'As for the Jackaroo, who can tell? Not I.'

Lisa remembered something that Chloe Millar had told her: the Jackaroo sometimes forbade things to make them more attractive. And she also remembered how the avatar had found those harmless tesserae in her house.

She said, 'Can they see what I see? Can they see ghosts?'

'Why not?'

'So they could have found and neutralised what's down there, the source of the breakout, long before Willie found it. Long before they gave us this world, and all the others. But they didn't.'

'Perhaps they do not know what will hurt you, and what will help.'

Lisa said, 'So how did they help you?'

'We did not need their help,' the !Cha said primly.

After a quick breakfast of granola bars and instant coffee, they retraced the route through the hills and then drove due west into the Badlands. Hour after hour skimming across alluvial fans and long stretches of rippled basement sand, skirting fleets of dunes. Following one of the old ceramic roads at first, then crossing a vast achingly flat playa towards the ghosts of mountains sketched at the horizon. Once, Lisa saw flickering movement off to the north: a translucent sketch of a giant figure got up from feathery fronds and bladders thrashing along. After a handful of seconds it blinked out, then reappeared at its starting point and thrashed forward again. She watched it spin past and recede and vanish into the playa's white glare, wondering if Unlikely Worlds saw it, wondering if he knew that she could see it.

At last, they stopped at a point no different from any other. Isabelle launched a sparrow-sized drone to keep watch, even though the playa was empty in every direction as far as the eye could see. They ate army rations. They slept, Isabelle in the Land Cruiser, Lisa on the ground again. It was fucking cold, but the night sky was awesome. The stars weren't uncountable, maybe five thousand or so, about the same the number that were visible from Earth, but they seemed to fill the black bowl of night from edge to edge. Stars everywhere Lisa looked. And presently the smoke of the North American nebula rose, a cloud of hydrogen gas roughly shaped like the continental USA and spread across a quarter of the sky, glowing red because it was ionised by hot stars embedded in it. One of them, Miro's Diamond, shining in the approximate location of Ottawa, was the brightest star in First Foot's sky. A massive blue-white O-type star that in a few million years, after burning through all of its hydrogen fuel, would bloat into a red supergiant and either explode as a supernova or evolve into a Wolf-Rayet star so hot that it would blow vast shells of glowing gas from its surface and form a nebula of its own. At more than two hundred light years away it would have little effect on First Foot, but future clients of the Jackaroo were going to have a spectacular view.

There was some perspective, if you wanted it.

A little later, the faint lodestar that nagged at Lisa's attention followed the chip of the moon above the western horizon. Wondering if it was Ada Morange's ship, she fell asleep tracking it, woke to find a wind had got up. The dawn sky was white with blowing dust and the sun, rising inside smeary shells of red light, looked twice its usual size.

Lisa and Isabelle sheltered from dust squalls in the Land Cruiser; Unlikely Worlds squatted outside, impervious. Lisa dozed off, was shaken awake by Isabelle, who shoved a tablet at her and started the Land Cruiser, saying, 'We're in deep trouble.'

'What about Unlikely Worlds?' Lisa said, as the Land Cruiser began to move. She was still half-asleep, cotton-mouthed, tangled in the fading remnants of a dream.

'We will come back for him,' Isabelle said. She was hunched over the steering wheel, peering ahead as the Land Cruiser accelerated through skittering squalls of dust, jolting over ripples and cracks in the playa floor. She looked tense and drawn. She looked like she had seen a ghost.

'What's wrong? Where are we going?' Lisa said.

'Check the tablet,' Isabelle said grimly.

Lisa studied the aerial view of the dust-blown playa. After a few moments, she made out a tiny figure glinting at the centre of the field of vision. She zoomed in: a grainy view of a Jackaroo avatar running at full tilt, naked, head down, arms pumping, dust puffing up from its feet.

'How did it get ahead of us?' she said.

'It didn't,' Isabelle said. 'The Jackaroo can make avatars from air and water, a few elements from dirt or plant life. I thought we were safe from that. The playa is mostly salt and gypsum. It is partly why we chose it as a landing place. But the Jackaroo must have found somewhere with the necessary elements. A seep, a pond, a place where plants grow. They made an avatar, and now it is coming for us. Luckily, the drone spotted it.'

Lisa remembered a famous video clip from the early days after First Contact: a shaky phone-cam image zooming in on a distant golden blur at the shore of a lake as it sharpened into human form, like a Star Trek special effect. She said, 'Is that why it's naked?'

'Yes. They cannot make clothes.'

The Land Cruiser was racing flat out, pedal to the metal. It thumped over something and was briefly airborne; when it landed, Isabelle wrestled with the steering wheel to straighten it out. Lisa buckled her seat belt, said, 'What are you going to do?'

'I must deal with it before the ship comes,' Isabelle said.

'Deal with it? You mean kill it?'

Isabelle glanced at her. 'You cannot kill something that is not actually alive. And I have been ordered to do it.'

'It doesn't mean you should.'

'What else can I do?'

'One avatar can't stop us.'

'We do not know what it can do,' Isabelle said.

'I didn't sign up for this.'

'It might want to kill you, Lisa. Because of your ghost. Did you not think of that?'

'That's crazy,' Lisa said, but she didn't quite believe that it was. At the very least, after her exposure to Willie's ghost, Adam Nevers and the Jackaroo would want to quarantine her. Stick her in some isolation facility for an indefinite period, basically life without the chance of parole, as sometimes happened to those infected with dangerous eidolons.

'We said that we would protect you,' Isabelle said. 'This is part of it.'

A couple of minutes later, a tiny figure appeared ahead. Lost in a scud of dust, appearing again, seeming to float towards them. 'Merde,' Isabelle said. Her knuckles were white on the steering wheel. Lisa wondered for a bare second if she should make a grab for it, and then the avatar was right there in front of them and there was a tremendous bang and something flew up and smacked into the windshield and was gone.

Isabelle braked hard in a cloud of dust, turned the Land Cruiser around and drove slowly back, stopped. She took a breath, then undid her seat belt and without a word to Lisa opened the door and stepped out. Lisa followed, shaky and apprehensive.

'It exploded when we hit it,' Isabelle said.

She was looking at something glinting on the dirty white ground, part of an arm or a leg. They walked about, found other fragments scattered across the crazed dry mud. A shattered hand, hollow as a glove. Splinters. They were already turning black, flaking, disintegrating, blowing away on the dusty wind.

Lisa and Isabelle climbed back into the Land Cruiser and followed its tracks towards the spot where they had left Unlikely Worlds.

'We will not talk about this with him,' Isabelle told Lisa.

'He'll want to know where we went, and why.'

'Yes, and I will tell him there was a small problem, taken care of. If he objects, he can find another ride.'

'He probably knows all about it, anyway,' Lisa said.

She was picturing the Jackaroo avatar, how it had been framed in the windshield a moment before the Land Cruiser struck it. It hadn't slowed as they'd borne down on it. It had kept running. And at the last moment it had looked up. Looked straight at her with eyes white as pebbles.

She was trying to work out what that look had meant. That the avatar knew who she was, maybe. Or maybe it hadn't been looking at her, but at her ghost . . . One thing was certain: the Jackaroo knew that she was riding in the vehicle that had smashed one of their avatars to splinters. Which meant that Adam Nevers probably knew, too. There was no way she could stay on First Foot now, but she also knew that she had put herself in the hands of some seriously ruthless characters.

Isabelle's q-phone warbled. 'Il est fait,' she told it. 'Oui, completement detruit.' Listening to someone talk, then saying, 'Dieu merci. Le plus tt sera le mieux.'

She switched off the q-phone, told Lisa that the ship was almost down. 'Don't worry. Everything will be okay.'

'Good,' Lisa said, thinking that everything was very far from fucking okay.

It didn't help that the first thing Unlikely Worlds said, when they got back, was, 'And how was the hunting?'

He knew, all right.

'We did what had to be done,' Isabelle said, with a pinched angry look at Lisa. 'And that is all I have to say.'

'This is turning out to be quite the adventure,' Unlikely Worlds said, but didn't ask any questions.

By unspoken agreement Lisa and Isabelle walked away in opposite directions from the !Cha and the Land Cruiser. Presently, a black speck appeared in the pale sky, quickly growing larger as it dropped towards them, falling silently down a fold it created in the planet's gravity field. A D-class yacht some forty metres from stem to stern. Lisa saw the spines piercing the black pineapple of its hull, thought of Willie. It halted with its flat stern about twenty metres above the ground and a few minutes later a hatch dilated with a busy movement like iron filings flowing around a magnetic pole. A rope flopped out and two men slid down it. They were dressed in coveralls and heavy boots, took off their work gloves to shake hands with Isabelle and Lisa.

After that, it was all business. A steel cable dropped, terminating in four straps that were each hooked around the Land Cruiser's wheels. Isabelle, Lisa and Unlikely Worlds climbed inside, the two men clambered onto the roof, and with a jerk and a jolt the vehicle swung off the ground.

The last Lisa saw of First Foot was a tilting horizon hazed with dust, a sliver of milky sky. And then the belly of the spaceship swallowed her.

40. Old Dark House.

'It isn't too late to go back to the ship,' Tony told the two clones. 'Or we could find an all-night cafe in the docks. Get out of this rain and drink tea and come back here in the morning, when I arranged to meet him. Do it right, instead of blundering in like thugs.'

'We do it this way or not at all,' Bob said.

'It is decided,' Bane said.

Shrouded in their hooded rain capes, they were standing in the archway to the courtyard where Adam Apostu's tall narrow house stood, as dark and quiet as its neighbours. It was the middle of the night. It was still raining. Rain slanted past the single lamp that lit the courtyard; rain hammered on wet flagstones; rain dripped from carved stones that edged the curve of the arch.

Raqle Thornhilde had decided that it would be best to strike early and surprise Adam Apostu. 'The man probably won't talk unless we strong-arm him,' she'd said, after Tony had objected. 'You know how these scholars are. They'd sooner starve than sell their so-called secrets. We'll give him a little tickling, and see what he gives up.'

Tony was not looking forward to that 'little tickling'. Despite his vow to do everything necessary to track down Aunty Jael and the Red Brigade, he did not think he could justify the torture of a harmless eccentric, and was worried that Adam Apostu might not survive the attention of Raqle's boys. Suppose he died before he yielded anything useful? Suppose he had connections that Tony had failed to uncover? They could probably outrun the local police, if it came to it, but there were plenty of powerful people who, like Raqle Thornhilde, could reach across worlds to exact revenge.

Unlikely Worlds, appearing to share Tony's misgivings, had declined to accompany what he called their little fishing expedition, claiming that he was interested in the stories people made of what they did, not the actual doing. And although Tony had told Raqle that they would learn more by using charm, flattery and bribes than by breaking bones or slicing off body parts, the broker was adamant.

'Have you forgotten what the Reds did to your home?' she said. 'This is no time for subtlety; this is a desperate and dangerous business. Quit bitching and get on with it. Or do I have to ask my boys to persuade you?'

Bane kept watch under the archway while Bob led Tony out into the rainy courtyard. The big man sprayed something around the edges of the door of Adam Apostu's house, told Tony to step back. A moment of silence, raindrops sizzling off the hoods and skirts of their rain capes. Then with a sharp crack and a blue flash the door fell flat on the wet flagstones, and Bob grabbed Tony's arm and hauled him across the threshold.

A single room occupied the ground floor, dark and unquiet. Little rustlings and squeaks. Flutterings. Bob floated a sparklight that revealed furniture piled everywhere, with only a narrow passage to the staircase on the far side. Shadows skittered under upturned chairs and tables, cat-sized and quick. Eidolons.

Tony could feel their attention prickling in his head, stepped back with electric shock when one reared up in front of him. It was pale and bone-thin, and had too many eyes studded around the dish of its face. He felt its attention push towards him, and then it recoiled and whirled away like a rag blown on a gust of wind.

'Up,' Bob said. 'Quick.'

Another dark room at the top of the stairs, bare floorboards and red curtains stretched from wall to wall. The sparklight cast Tony's and Bob's shadows across the curtains' heavy folds; the shadows rippled as something stirred and parted them.

A man stepped through, dressed in a long black gown whose hood covered most of his head. His face was mild and milk-white; his eyes were masked by glasses with round black mirrors for lenses. He pulled a wheeled pole with him as he took two tentative steps into the room. His free hand, white-gloved, groped the air and he asked in a high quavering voice, 'Who are you? Why have you disturbed me?'

Tony realised that the man, Adam Apostu, was blind and ill. A transparent sac hung from the top of his pole, and a line looped from it to a slit in the waist of his gown.

'We come for answers, not questions,' Bob said.

Tony pushed back the hood of his rain cape and said, 'I want to discuss stromatolites and Ghajar algorithms.'

'You are early for your appointment. And there was no need to enter by force. As you can see, I am a harmless old man, not at all like the monster they told you about.'

Adam Apostu's lips scarcely moved when he spoke. His skin was caked with white powder and seemed to be as stiff as leather. Tony wondered if it was a symptom of his illness.

'I was told that you never leave this house,' Tony said. 'Yet you know that we were asking about you.'

'I don't go out because I prefer people to come to me. And I have no need of food, as this drip sustains my body. But I have my mice, and my mice have ears,' Adam Apostu said. 'They go everywhere in the city, and most people don't notice them. They travel the paths of the dead. Speaking of the dead, how is the guest in your head?'

Tony was too surprised to deny it. 'Who told you about that?'

Before the scholar could reply, Bob said, 'We don't care about your mice, or about dead people either. We want to know what you know about Ada Morange and the Red Brigade.'

Tony said, 'Ada Morange is a laminated brain owned by my family. She also goes by the name of Aunty Jael. Do you know her?'

'Of course,' Adam Apostu said.

Tony was surprised by the man's candour. He said, 'Have you spoken to her? Did she tell you about the slime planet?'

If he kept Adam Apostu talking, there would be no need for Bob's tickling.

'I learned about it in records that no one else had bothered to access for fifty years. People commonly say that much knowledge was lost in the various wars when the two empires rose and fell. But it's more accurate to say that most of it was misplaced. You just have to know how to look for it.'

'Did you share your find with Ada Morange? Did she suggest that you offer it to Raqle Thornhilde?'

'I sold the details of the slime planet to Raqle Thornhilde. And also suggested that she hire you.'

Tony looked at Bob. 'Is this true?'

'He lies,' Bob said, and shucked off his rain cape and drew a knife with a long thin blade. 'This is my tickler, old man. I use it to tickle the truth out of people. First I'll cut your food line. Then I'll start cutting you.'

Tony said quickly, 'He won't hurt you if you tell the truth.'

'But I am telling the truth.' The scholar seemed to be amused.

Tony said, 'Why use a third party? Why not tell my family directly?'

'Would you have believed a humble and obscure scholar such as me? I knew you were working out of Dry Salvages, so I contacted one of the brokers there, told her about the slime planet, and pointed her towards you. But I see now that she is dissatisfied with the arrangement.'