Sri Hong-Owen and her eldest son, Alder, travelled to Callisto in a small freighter, the Luis Inacio da Silva, that had been fitted with a prototype of the new fusion motor. It cut the record for transit between Earth and Jupiter by two-thirds, a fine demonstration of the Peixoto family's technological prowess, and an important contribution to their elaborate and extensive sales pitch to the Callistans. Sri had a packed schedule: touring farms and factories and laboratories, meeting with the Callistan Senate and leading citizens of Rainbow Bridge, taking part in a ceremony to mark the first stage of the quickening of the biome's lake, and so on and so forth. And she wanted to meet the gene wizard Avernus, too. First of all, though, she needed to straighten out the tangled business of the failed attempt at sabotage, the murder of Ursula Freye, and the defection of Macy Minnot, so she made room in her schedule for a meeting with the junior diplomat who seemed to be in the middle of it all.

Loc Ifrahim was summoned to Sri Hong-Owen's suite the day after she arrived. It was the penthouse of an apartment complex built into one of the huge struts of the biome's tent. He arrived precisely on time, was scanned and sniffed by Sri Hong-Owen's secretary, and left to kick his heels in the foyer. He supposed that the wait was meant to put him in his place and heighten any anxieties he might be harbouring, but he didn't let it touch him. It gave him time to go over his story again, and he could watch people come and go. He liked watching people, trying to work out their motives, trying to figure out what they might be thinking, whether or not they might be useful to him.

Presently, the pair of peace officers who had interviewed him about Ursula Freye's death came out of Sri Hong-Owen's suite. One, a tall, severe woman with a square of white hair sitting on top of her head like a cap of snow, smiled coldly at Loc and asked if he was going to be more cooperative with his boss than he had been with her.

Loc returned her smile. 'Professor Doctor Hong-Owen isn't my "boss". I work for the Brazilian government, not the Peixoto family.'

'I have the impression that you're more interested in yourself.'

'And I can't help thinking that if your city was as interested in this project as it claims to be, it would not be harbouring Macy Minnot,' Loc said.

'We both know that she had nothing to do with Ursula Freye's murder,'

the white-haired peace officer said.

'I know no such thing. In fact, I have given you evidence to the contrary. Evidence you have chosen to ignore.'

'Waive your diplomatic immunity,' the peace officer said. 'Then I'll be glad to discuss your so-called evidence.'

Her gaze burned with frustration and anger. Loc had agreed to a brief interview with the city's peace officers after Ursula Freye's death and Macy Minnot's defection, but they hadn't been allowed to interrogate him formally, let alone test him with an MRI cap; all they'd been able to do was listen to his statement, ask a few polite questions, and let him go. There'd been some loose talk in the Callistan Senate about expelling him, but it hadn't amounted to anything because there was nothing that directly linked him to Ursula Freye's death, and no one wanted to risk precipitating a diplomatic incident that could wreck the trade talks and the opening of the biome.

'Leave him, Dee,' the peace officer's partner said. 'He's just a bit player.'

'I'll be right behind you if there's any more trouble,' the white-haired peace officer told Loc, and turned away.

'Why would there be any more trouble now that Macy Minnot is in your tender care?' Loc said loudly as the peace officers walked towards the belt of rising and falling platforms that passed for an elevator here. Sri Hong-Owen's secretary glanced up from the slate he was nursing, but the peace officers didn't even look back.

Well, screw them. They'd made threatening noises during their investigation of Ursula Freye's murder, but they hadn't be able to touch him. They hadn't even been able to touch that oafish blunderer Speller Twain. No doubt they'd been doing their best to poison Sri Hong-Owen with their suspicions, but Loc had already anticipated that. He had everything covered.

At last, he was ushered into the suite. It was mildly impressive, a cavernous space with a halflife lawn that blended seamlessly into the virtual backdrop of the walls, depicting herds of extinct and fantasy animals grazing on a plain that stretched to distant mountains. Sri Hong-Owen was waiting for him at the far end, standing in the shade of a grove of bamboos and ferns that grew amongst a litter of big rocks. A slight, slender woman dressed in a tailored version of the green coveralls of the construction crew, her eyes masked by spex with silvered lenses and chunky black frames, her naked scalp as translucently pale as a porcelain bowl. Loc shuffled towards her in his grippy slippers, bowed as low as he dared, and said that he was at her service.

'We'll sit,' Sri Hong-Owen said, and two flat-topped hummocks pushed up from the emerald-green turf.

They sat facing each other, knees almost touching.

'I've read the report about the circumstances of Miz Freye's death,'

Sri Hong-Owen said. 'Now I want to hear your version of events. Your point of view, your insights. Every little detail.'

Loc had heard that the gene wizard had a reputation for impatience and frank speaking; even so, he was taken aback by this shocking directness. She appeared to believe that he was some kind of indentured servant answerable directly to her, but he ignored the insult to his status because he needed to charm her, and laid out his version of events with calm, fluent authority. Explaining that Emmanuel Vargo's lover, Ursula Freye, had insisted that his death hadn't been accidental, that he'd been murdered by a person or persons trying to sabotage the construction project. There were no grounds for her accusation beyond the fact that Emmanuel Vargo's slate had gone missing, but because she was consanguineous with the Fontaine family Euclides Peixoto hadn't been able to dismiss her case outright. He'd instructed Speller Twain, the construction crew's security chief, to deal with the problem as he saw fit, and Speller Twain had approached the embassy for help.

'Like Mr Twain, the ambassador was wary of becoming entangled in political complications. And so the task fell to the most junior staff member, namely me,' Loc Ifrahim said, with a small, self-deprecating smile. 'Mr Twain and I decided to enlist the help of the other member of the Fontaine family in the construction crew, Macy Minnot. At our urging, she attempted to reason with Ursula Freye, but Miz Freye not only refused to give up her crusade, she also asked Miz Minnot to help her by obtaining a copy of the construction crew's work logs. She wanted to examine it for evidence of sabotage, you understand, and she could not obtain it herself. As a precaution, Mr Twain had taken away her access privileges.'

'Why did he do that?'

'Actually, I advised him to do it. I was worried that Ursula Freye might be tempted to alter the records to support her contention that Emmanuel Vargo had been murdered. She seemed quite irrational, you see. Capable of anything.'

'Ah. Then she was not locked out because you were worried that she might find some inconvenient truth.'

'Not at all. We gave Miz Minnot permission to make a copy of the work logs and hand it to Ursula Freye. A few days later, Miz Freye claimed to have discovered something important. She arranged a meeting with Miz Minnot, but we intervened and tried to talk to her.'

Sri Hong-Owen said, 'And did Miz Freye tell you what she had found?'

Loc knew that the woman had uncovered the data Speller Twain had added to the work logs just before Macy Minnot had copied them, subtle clues hinting at a conspiracy involving Cristine Quarrick and Patrick Alan Allard and tied to the very real sabotage of one of the microalgal cultures, but he was able to say truthfully that Ursula Freye had been most uncooperative.

'After we let her go, she must have gone to talk with Macy Minnot. The surveillance system in the biome crashed, and Miz Freye was killed. Mr Twain gave chase, but Macy Minnot managed to escape.'

'She shot him with his own taser, I believe.'

'Yes, ma'am. After someone used a drone to knock him down.'

'Where were you while this was happening?'

Sri Hong-Owen was leaning forwards, hands planted on her knees. Loc could see himself doubly reflected in the silvery lenses of her spex. He was certain that she was studying the dilation of his pupils and the blood flow in the skin capillaries of his face, looking for cues that might indicate that he was lying, but he was confident that his training would foil any attempt to catch him out. Besides, apart from the omission of a few inconvenient facts, his story was more or less truthful.

He said, 'I was nearby, using a drone to keep watch on Macy Minnot. Until the system fell over, that is.'

'So you didn't see who killed Ursula Freye.'

'Not until the drone came back online. As soon as it did, I had it follow Macy Minnot. Unfortunately, she shot it down with the taser she'd taken from Mr Twain. I attempted to follow her myself, but she managed to get away.'

'She overpowered Mr Twain, and then she got the better of you.'

'She served in the Reclamation and Reconstruction Corps before she was recruited for the construction crew. She had military training. And I regret that, unlike Mr Twain, I am not a man of action.'

'Mr Twain claims that he saw her shoot Ursula Freye in the head with a nail gun,' Sri Hong-Owen said.

'He gave a statement to that effect, ma'am. I believe that the murder weapon was part of the equipment issued to Miz Minnot's laboratory, and was later retrieved from the lake.'

Where Speller Twain, the damn fool, had thrown it.

'Mr Twain also claims that Ursula Freye murdered Emmanuel Vargo,'

Sri Hong-Owen said. 'Do you believe that?'

'It's certainly true that Miz Freye was one of the last people to see Mr Vargo before the crew was put to sleep,' Loc said. 'And after her death, Mr Twain discovered Mr Vargo's slate in her quarters. He thinks that she could have infected Mr Vargo with an agent that caused his death from pseudo-CND when he was revived. But I have to admit that I can't quite square that with Miz Freye's very loud and persistent claims that he was murdered, especially as everyone else was ready to accept that it was an accident. It's a very troubling inconsistency.'

'Does Mr Twain have any hard evidence for these suppositions?' Sri Hong-Owen said. 'Apart from the discovery of Mr Vargo's slate, which could easily have been planted.'

'Mr Twain claims that Miz Freye and Miz Minnot were working together to sabotage the project, and had a falling-out. Unfortunately, Miz Minnot left Rainbow Bridge the day after she defected,' Loc said. 'Aboard a tug named The Long March that took her to the city of East of Eden, Ganymede. The tug is owned by a man named Galileo Wu. Mr Wu is the grand-uncle of Loris Sher Yanagita, and Miz Yanagita not only worked as Miz Minnot's assistant; she is also the daughter of one of the members of Callisto's Senate.'

He was beginning to enjoy himself. After Macy Minnot's escape, his quick thinking had pulled everything back from the brink of disaster, and he was confident that he could pin the deaths of Emmanuel Vargo and Ursula Freye on a new scapegoat. All he had to do was sow some seeds of doubt in the minds of Euclides Peixoto and this so-called gene wizard, and then his new friends would tie up the loose ends.

'So Miz Minnot has serious protection,' Sri Hong-Owen said.

'Indeed. We asked to speak with her immediately after she defected, but our request was refused. We tried again after she was moved to East of Eden, and again our request was refused. And without access to Miz Minnot it has not been possible to take the investigation any further.'

'What about the Fontaine family?'

'They would have to pay a great deal to reach that far, but since she is suspected of murdering a family member with one-thirty-second consanguinity, I would not rule it out.'

'Even though the Fontaines have disowned Ursula Freye.'

Loc smiled. 'Well, they would, wouldn't they? The affair has caused them considerable trouble. And even if Miz Minnot was carrying out their orders, they are hardly likely to welcome her back.'

Sri Hong-Owen studied him for a moment, then said, 'Let me show you something.'

He followed her around the bamboos and rocks to a glass blister that clung like a raindrop to the slanting side of the great strut. Sri Hong-Owen walked straight across it but Loc halted in the doorway: the blister's floor was as transparent as its curved wall. Far below, water lapped the rocky shoreline of the lake.

'We can talk safely here,' Sri Hong-Owen said, turning to Loc. She seemed to be floating in midair. 'My people found several bugs planted in the suite, but they can't be certain that they found everything. This, though, is quite sterile. The glass is one-way, and a little engine vibrates it to prevent anyone eavesdropping. Come in, and shut the door.'

Loc did as he was told, taking a single step onto the glass floor. He was certain that the gene wizard wanted something from him. Information, a favour, something he could give her now and draw on later.

'I had an interesting conversation with the peace officers investigating Miz Freye's murder,' Sri Hong-Owen said.

'I couldn't help noticing them leave,' Loc said. He didn't want to antagonise the gene wizard, not now, when she was about to put her trust in him, so he didn't add that he knew that the confrontation had been staged in a clumsy attempt to unnerve him.

'They told me that Miz Freye was killed by a nail fired into her medulla oblongata,' Sri Hong-Owen said. 'It killed her instantly. Either the person who murdered her was very lucky, or they knew exactly what they were doing. Also, the wound track indicates that the nail gun was angled downwards when it was fired, and bruising of the skin of Miz Freye's hands and neck suggest that she was seized from behind before she was shot, and her wrists were pinioned. That isn't consistent with Mr Twain's claim that he saw Miz Minnot and Miz Freye struggle. And although Miz Freye was shot at close range, the peace officers found no trace of blowback on the clothes Miz Minnot left behind in the airlock when she escaped from the biome. No blood, no bone or brain fragments consistent with a close-range shot. There were traces of blood on Miz Minnot's fingers, yes, but she told the peace officers that she had checked Miz Freye's pulse. Then there is the question of the lack of fingerprints and DNA on the murder weapon. Perhaps Miz Minnot was wearing gloves, but none were found. She certainly was not wearing them when she got Miz Freye's blood on her fingers. In short, Mr Ifrahim, the peace officers do not believe that Miz Minnot killed Miz Freye. And they do not believe Mr Twain's witness statement, either. So let me ask you directly: do you think that she did it?'

Here it was. Loc let a little concern show on his face and said, 'I have given you the official story. But now that we can speak freely? No. No, I don't think that Macy Minnot killed Ursula Freye.'

'Who did?'

'I think we both know the answer, ma'am.'

'Mr Twain killed Ursula Freye, and he would have killed Macy Minnot too. But she escaped.'

'I imagine he planned to claim that Miz Minnot died while trying to evade arrest. The murder weapon came from a tool kit in her laboratory, and the viral program that took down the surveillance system appeared to originate from her slate. I confess, I would have believed him.'

'And did he also kill Emmanuel Vargo?'

'I suppose it's possible,' Loc said, as if the thought had only just occurred to him.

'You are also under suspicion, I believe.'

'If I am guilty of anything, it is naivety. I trusted Mr Twain too readily, and I am thoroughly ashamed of my part in his machinations. Most especially as he is free to act again.'

'What do you mean?'

A small slick of pleasure seeped into Loc's heart. He had her. He knew that he had her. 'After the discovery of the corrupted diatom culture, the construction crew have been checking everything they brought with them. No trace of any other attempt at sabotage has been found. And Outers working alongside our people have grown up a fresh culture of the diatom, so the quickening of the lake will not be delayed. But it isn't hard to imagine that Mr Twain may be planning some form of direct action. Assassination, perhaps.'

'And who might he be planning to assassinate?'

'I regret that it is quite possible that you may be his target, ma'am. You, or Avernus.'

'If she comes here, and we don't yet know if she will. Have you told the ambassador or Euclides Peixoto about your suspicions?'

'Alas, no. I have no evidence, and the ambassador has made it clear that he believes that the affair is at an end. And Mr Peixoto, with respect, is somewhat . . . disengaged.'

Sri Hong-Owen nodded. 'That's true enough. Mr Peixoto was given his position by an uncle who is more fond of him than he deserves.'

Loc knew that her indiscretion meant he was winning her trust. 'If there is anything I can do for you, anything at all, you have only to ask.'

'And what about your oath of loyalty to the government?'

'The government exists to serve the families, ma'am.'

'How old are you, Mr Ifrahim?'

'Twenty-five.'

'Twenty-five. You were born in the slums of Caracas, I believe. You have come a long way, and very quickly. You must be very ambitious.'

'I want to serve as best I can, ma'am.'

'You really are quite a creature, Mr Ifrahim.' Sri Hong-Owen turned to the view beyond the glass wall of the blister and said, 'Come here. Stand by me.'

Loc shuffled across the transparent floor, his toes cramping in his slippers, a vast and airy unease yawning in his belly.

Sri Hong-Owen was staring past her faint reflection in the blister's glassy curve, looking out at the lake and its scattering of green islands mapped between the leaning and faceted walls of the Home's tent.

'It's magnificent,' she said. 'It's hard to believe that twenty thousand people huddled on an icy moon far from the sun could be capable of anything on this scale. And yet it was built and pressurised and landscaped in less than a year. Do you know how they did it?'

'They have many robots-'

'Knowledge,' Sri Hong-Owen said. 'They have preserved much that Earth lost in the aftermath of the Overturn. And they have been adding to it ever since, while we spend most of our resources on reclamation and reconstruction. Which is good work, of course. Necessary work. Noble work. But think of how much more we could do if we had full control of the technologies and scientific knowledge preserved and developed by the Outers. That's why the Peixoto family agreed to Avernus's offer, why they sent out the construction crew to quicken this biome. For many years now they have been attempting reconciliation between Earth and the Outer System. This is a major step in that campaign. A show of faith. The beginning of what may be a long and fruitful trade partnership with the Outers.

'Like you, Mr Ifrahim, I'm an employee. You work for the government; I work for the Peixoto family. But I'm sure you're aware that the potential rewards of this enterprise are so great that even humble employees like myself can hope for some small share. As long as we always put the family's interests before those of ourselves. As long as we are unfailingly and unflinchingly loyal.'

Loc pretended to take offence. 'I would hope that my candour about this wretched affair is proof enough that I want to help.'

'It's obvious that Mr Twain murdered Ursula Freye. If you truly want to help me, you are going to have to do better than that.'

Really, he could have kissed her. Not only had she swallowed his story whole; she also believed that he was truffling for titbits in return for favours. He said, 'Mr Twain has already damaged your project, and he is almost certainly in league with people who wish to cause it further damage. Let me find out all I can. Then, perhaps, I can help you find a way to overcome the threat he poses.'

10.

Later, Sri Hong-Owen said to her son, 'Can I trust him?'