'Then we have to accept my solution,' Gallinule said. 'Become software. It can be done, you know. In a few months we'll have the technology to scan ourselves.' He held up the mouse again. 'See this little fellow? He was the first. I scanned him a few days ago.'

  Merlin stared at the mouse.

  'This is really him,' Gallinule continued. 'Not simply a projection of a real mouse into the Palace's environment, or even a convincing fake. Slice him open and you'd find everything you'd expect. He only exists here now, but his behaviour hasn't changed at all.'

  'What happened to the real mouse, Gallinule?'

  Gallinule shrugged. 'Died, of course. I'm afraid the scanning procedure's still fairly destructive.'

  'So the little catch in your plan for our salvation is that we'd have to die to get inside your machine?'

  'If we don't do it, we die anyway. Not much to debate, is there?'

  'Not if you put it in those terms, no. We could of course experiment with the final syrinx and find a better way to escape, but I suppose that's too much of an imaginative leap for anyone to make.'

  'Except you, of course.'

  They were silent for long moments. Merlin stared out to sea, the Palace's reality utterly solid to him now. He did not think that it felt any less real to the mouse. This was how it could be for all of them, if Gallinule had his way: inhabiting any environment they liked until the Husker threat was over. They could skip over that time if they wished, or spend it exploring a multitude of simulated worlds. The trouble was, would there be anything to lure them back into the real world when the danger had passed? Would they even bother remembering what had come before? The Palace was already tantalising enough. There had been times when Merlin had found it difficult to leave the place. It was like a door into his youth.

  'Gallinule . . .' Merlin said. 'There's something I always meant to ask you about the Palace. You've made it as real as humanly possible. There isn't a detail out of place. Sometimes it makes me want to cry, it's so close to what I remember. But there's something missing. Someone, to be exact. Whenever we were here - back in the real Palace, I mean - then she was always here as well.'

  Gallinule stared at him in something like horror. 'You're asking me if I ever thought of simulating Mother?'

  'Don't tell me it hasn't crossed your mind. I know you could have done it as well.'

  'It would have been a travesty.'

  Merlin nodded. 'I know. But that doesn't mean you wouldn't have thought of it.'

  Gallinule shook his head slowly and sadly, as if infinitely disappointed by his brother's presumption. In the silence that followed, Merlin stared out at the shadow-matter object that hung over the sea. Whatever happened now, he thought, things between him and Gallinule could never be quite the same. It was not simply that he knew Gallinule was lying about their mother. Gallinule would have tried recreating her; anything less would have been an unforgivable lapse in his brother's devotion to detail. No; what had truly come between them was Sayaca. She and Gallinule were lovers now, Merlin knew, and yet this was something that he had never discussed with his brother. Time had passed and now there seemed no sensible way to broach the subject. It was simply there - unavoidable, like the knowledge that they would probably all die before very long. There was nothing to be done about it, so no point in discussing it. But in the same moment he realised something else, something that had been nagging at the back of his mind since the very earliest maps of the anomaly had been transmitted.

  'Expand the scale,' he said. 'Zoom out, massively.'

  Gallinule looked at him wordlessly, but obeyed his brother all the same. The anomaly shrank towards invisibility.

  'Now show the anomaly's position within the system. All planetary positions to be exactly as they are now.'

  A vast, luminous orrery filled the sky: concentric circles centred on Bright Boy, with nodal points for the planets.

  'Now extend a vector with its origin in the anomaly, parallel to the anomaly's long axis. Make it as long as necessary.'

  'What are you thinking?' Gallinule said, all animosity gone now.

  'That the anomaly was only ever a pointer, directing our attention to the really important thing. Just do it, will you?'

  A straight line knifed out from Ghost - the anomaly insignificant at this scale - and cut across the system, towards Bright Boy and the inner worlds.

  Knifing straight through Cinder.

  PART FIVE

  'I wanted you to be the first to know,' Sayaca said, her semblance standing regally in his quarters like a playing-card monarch. 'We've found signals coming from inside the planet. Gravitational signals - exactly what we'd expect if someone in the shadow universe was trying to contact us.'

  Merlin studied the beautiful lines of her face, reminding himself that all he was speaking to was a cunning approximation of the real Sayaca, who was light-hours of communicational time-lag down-system.

  'How do they do it? Get a signal across, I mean.'

  'There's only one way: you have to move large masses around quickly, creating a high-frequency ripple in space-time. They're using black holes, I think: miniature ones, like the thing you first thought we'd found in Ghost. Charged up and oscillated, so that they give off an amplitude-modulated gravitational wave.'

  Merlin shrugged. 'So it wasn't such a stupid idea to begin with.'

  Sayaca smiled tolerantly. 'We still don't know how they make and manipulate them. But that doesn't matter for now. What does is that the message is clearly intended for us. It's only commenced since we reached into Cinder's deeper layers. Somehow that action alerted them - whoever they are - to our presence.'

  Merlin shivered despite himself. 'Is there any chance that these signals could be picked up by the Huskers as well?'

  'Every chance, I'd say - unless they stop before they get here. Which is why we've been working so hard to decode the signal.'

  'And you have?'

  Sayaca nodded. 'We identified recurrent patterns in the gravitational signal, a block of data that the shadow people were sending over and over again. Within this block of data were two kinds of bits: a strong gravitational pulse and a weaker one, like a one and zero in binary notation. The number of bits in the signal was equal to the product of three primes - definitely not accidental - so we reassembled the data-set along three axes, forming a three-dimensional image.' Sayaca paused and lifted her palm. What appeared in mid-air was a solid rectangular form, slab-sided and featureless. It rotated lazily, revealing its blankness to the audience.

  'Doesn't look like much,' Merlin said.

  'That's because the outer layer of the solid is all ones. In fact, only a tiny part of its volume is made up of zeroes at all. I'll remove the ones and display only the zero values . . .'

  A touch of showmanship: the surface of the box suddenly seemed to be made out of interlocking birds, frozen in formation for an instant before flying in a million different directions. Suddenly what she was showing him made a lot more sense. It was like a ball of loosely knotted string. A map of Cinder's crustal tunnels, plunging more deeply towards the core than their own maps even hinted. Five or six hundred kilometres into the lithosphere.

  'But it doesn't tell us anything we wouldn't have learned eventually--' Merlin said.

  'No; I think it does.' Sayaca made the image enlarge, until she was showing him the deep end of one particular tunnel. It was capped by a nearly spherical chamber. 'All the other shafts end abruptly, even those that branch off from this one at higher levels. But they've clearly drawn our attention to this chamber. That has to mean something.'

  'You think there's something there, don't you?'

  'We'll know soon enough. By the time this semblance speaks to you, Gallinule and I will have almost reached that chamber. Wish us the best of luck, won't you? Whatever we find in there, I'm fairly certain it'll change things for us.'

  'For better or for worse?'

  The semblance smiled. 'We'll just have to wait and see, won't we?'
r />   End times, Merlin thought again. He could taste it in the air: quiet desperation. The long-range sensors sprinkled around the system had picked up the first faint hints of neutrino emission, which might originate with Husker craft moving stealthily towards Bright Boy from interstellar space. And the main swarms up and down the length of the Way had not gone away.

  One or two humans had undergone Gallinule's fatal scanning process now, choosing to go ahead of the pack rather than wait for the final stampede. Their patterns were frozen at the moment, but before very long Gallinule's acolytes would weave a simulated environment that the scanned could inhabit. Then, undoubtedly, others would follow. But not many. Merlin was not alone in flinching at the idea of throwing away the flesh just to survive. There were some prices that were simply too high, simply too alien.

  Do that, he thought, and we're halfway to being Husker ourselves.

  What could he do to save himself, if saving the rest of them was out of the question? He thought of stealing the syrinx. He had not learned enough to use it safely yet, but he knew he was not far from being able to do so. But it was tightly guarded, under permanent Council scrutiny. He had asked Gallinule and Sayaca to apply persuasion to the others, but while they might have had the necessary influence, they had not acceded to his wishes.

  And now Sayaca was back from Cinder, bearing tidings. She had convened a meeting again, but this time nobody was going to steal her thunder.

  Especially as she had brought someone with her.

  It was the semblance of a woman: a female of uncertain age but from approximately the same genetic background as everyone present. That was nothing to be counted on; since the Flourishing there had been many splinters of humanity, many of which seemed monstrously strange to those who had remained loyal to the old phenotype. But had this woman changed her clothes, make-up and hairstyle, she could have walked amongst them without attracting a second glance. Except perhaps for her beauty: something indefinably serene in her face and bearing that seemed almost supernatural.

  Her expression, before she began speaking, was one of complete calm.

  'My name is Halvorsen,' she said. 'It's an old name, archaic even in my own time . . . I have no idea how it will sound to your ears, or if you can even understand a word of what I'm saying. We will record versions of this message in over a thousand languages, all that we hold in our current linguistics database, in the hope that some distant traveller will recognise something, anything, of use.'

  Merlin raised a hand. 'Stop . . . stop her. Can you do that?'

  Sayaca nodded, causing Halvorsen to freeze, mouth open.

  'What is she?' Merlin said.

  'Just a recording. We triggered her when we arrived in the chamber. It wasn't hard to translate her. We already knew that the Diggers' language would later evolve into Main, so it was just a question of hoping that one of the recordings would be in a tongue that was also in our records.'

  'And?'

  'Well, none of her messages were in languages we knew moderately well. But three were in languages for which we had fragments, so we were able to patch together this version using all three threads. There are still a few holes, of course, but I don't think we'll miss anything critical.'

  'You'd better hope not. Well, let her - whoever she is - continue.'

  Halvorsen became animated again. 'Let me say something about my past,' she said. 'It may help you establish the time frame in which this recording was made. My ancestors came from Earth. So did yours - if you are at all human - but in my case I even met someone who had been born there, although it was one of her oldest memories, something as faint and tiny as an image seen through the wrong end of a telescope. She remembered a time before the Flourishing, before the great migrations into the Orion Arm. We rode swallowships for ten thousand years, cleaving close to light-speed. Then came wars. Awful wars. We hid for another ten thousand years, until our part of the galaxy was quiet again. We watched many cultures rise and fall, learning what we could from them; trading with those who seemed the least hostile. Then the Waymakers came, extending their transit network into our region of space. They were like gods to us as well, although we stole some of their miracles and fashioned them to our own uses. After thousands of years of careful study we learned how to make syrinxes and to use the Waynet.' She paused. 'We had a name for ourselves too: the Watchers.'

  Halvorsen's story continued. She told them how a virus had propagated through their fleets, subtly corrupting their most ancient data heirlooms. By the time the damage was discovered, all their starmaps had been rendered useless. They no longer knew where Earth was. At first, the loss seemed of minimal importance, but as time passed, and they came into contact with more and more cultures, it became clear that the Watchers' records had probably been the last to survive uncorrupted.

  'That was when she died, the oldest of us. I think until then she had always clung to some hope that we would return to Earth. When she knew it could never happen, she saw no reason to continue living.'

  Then they entered a long Dark Age. The Waymakers had gone; now, unpoliced, terrors were roaming the galaxy. Marauders sought the technological wisdom that the Watchers had acquired over slow millennia. The Watchers fled, pursued across the light-years in much the same manner as the Cohort now found itself, hounded from star to star. Like the Cohort too, they found Bright Boy. They were exploring it, trying to understand the system's anomalies; hoping that the understanding would bring new power over their enemies. They had excavated the tunnel system into Cinder and created the machines that lined the terminal chamber. They too had detected signals from the shadow universe, although the contents of the messages proved much harder to decode.

  'They were alien,' Halvorsen said. 'Truly alien: automated transmissions left behind half a billion years earlier by a group of creatures who had crossed over into the shadow universe. They had been fleeing the fire that was about to be unleashed by the merger of a pair of binary neutron stars only a few hundred light-years away. They left instructions on how to join them. We learned how to generate the same kinds of high-frequency gravitational waves that they were using to signal us. Then we learned how to encode ourselves into those wave packets so that we could send biological information between universes. Although the aliens were long gone, they left behind machines to tend to us and to take care of our needs once we were reassembled on the other side.'

  'But the Marauders are long gone,' Merlin said. 'Our oldest records barely mention them. Why didn't Halvorsen and her people return here?'

  'There was no need,' Sayaca said. 'We tend to think of the shadow universe as a cold, ghostly place, but once you're mapped into it, it looks much like our own universe - the sky dotted with bright suns, warm worlds orbiting them. Theirs for the taking, in fact. Halvorsen's people had been late-players in a galaxy already carved up by thousands of earlier factions. But the shadow universe was virgin territory. They no longer had to skulk around higher powers, or hide from outlaw clades. There was no one else there.'

  'Except the aliens . . . the--' Merlin blinked. 'What did she call them?'

  Sayaca paused before answering. 'She didn't. But their name for them was the . . .' Again, a moment's hesitation. 'The Shadow Puppets. And they were long gone. They'd left behind machines to assist any future cultures who wanted to make the crossing, but there was no sign of them now. Maybe they moved away to settle some remote part of the shadow galaxy, or maybe they returned to our universe when the threat from the merger event had passed.'

  'Halvorsen's people trusted these creatures?'

  'What choice did they have? Not much more than us. They were in as much danger from the Marauders as we are from the Huskers.'

  It was Halvorsen who continued the story. 'So we crossed over. We expanded massively; extended a human presence around a dozen nearby systems on the other side. Star travel's difficult because there's no Waynet, but the social templates we acquired during the time before the Marauders have served us well. We've been
at peace for one thousand years at the time of this message's recording. Many more thousands of years are likely to have passed before it reaches you. If we attempted to communicate with you gravitationally, then you can be sure that we're still alive. By then we will have studied you via the automated systems we left running in Cinder. They will have told us that you are essentially peaceable; that we are ready to welcome you.'

  Halvorsen's tone of voice changed now. 'That's our invitation, then. We've opened the gateway for you; provided the means for information to pass into the shadow universe. To take the next step, you must make the hardest of sacrifices. You must discard the flesh; submit yourselves to whatever scanning techniques you have developed. We did it once, and we know it's a difficult journey, but less difficult than death. For us, the choice was obvious enough. For you, it may not be so very different.' Halvorsen paused and extended a hand in supplication. 'Do not be frightened. Follow us. We have been waiting a long time for your company.'