It was Zima Blue: the same shade of blue as on the gold-lettered card.

  Over the next decade or so, the abstract shapes became more dominant, squeezing out the other elements of each composition. The cosmic vistas ended up as narrow borders, framing blank circles, triangles, rectangles. Where his earlier work had been characterised by exuberant brushwork and thick layers of paint, the blue forms were rendered with mirror-smoothness.

  Intimidated by the intrusion of the abstract blue forms, casual buyers turned away from Zima. Before very long Zima unveiled the first of his entirely blue murals. Large enough to cover the side of a thousand-storey building, the mural was considered by many to be as far as Zima could take things.

  They couldn't have been more wrong.

  I felt the conveyor slowing as we neared a small island, the only feature in any direction.

  'You're the first to see this,' the robot said. 'There's a distortion screen blocking the view from space.'

  The island was about a kilometre across: low and turtle-shaped, ringed by a narrow collar of pale sand. Near the middle it rose to a shallow plateau, on which vegetation had been cleared in a roughly rectangular area. I made out a small panel of reflective blue set flat against the ground, surrounded by what appeared to be a set of tiered viewing stands.

  The conveyor shed altitude and speed, bobbing down until it stopped just outside the area enclosed by the viewing stands. It came to rest next to a low, white pebble-dash chalet I hadn't noticed during our approach.

  The robot stepped out and helped me from the conveyor.

  'Zima will be here in a moment,' it said, before returning to the conveyor and vanishing back into the sky.

  Suddenly I felt very alone and very vulnerable. A breeze came in from the sea, blowing sand into my eyes. The sun was creeping down towards the horizon and soon it would be getting chilly. Just when I was beginning to feel the itch of panic, a man emerged from the chalet, rubbing his hands briskly. He walked towards me, following a path of paved stones.

  'Glad you could make it, Carrie.'

  It was Zima, of course, and in a flash I felt foolish for doubting that he would show his face.

  'Hi,' I said lamely.

  Zima offered his hand. I shook it, feeling the slightly plastic texture of his artificial skin. Today it was a dull pewter-grey.

  'Let's go and sit on the balcony. It's nice to watch the sunset, isn't it?'

  'Nice,' I agreed.

  He turned his back to me and set off in the direction of the chalet. As he walked, his muscles flexed and bulged beneath the pewter flesh. There were scalelike glints in the skin on his back, as if it had been set with a mosaic of reflective chips. He was beautiful like a statue, muscular like a panther. He was a handsome man, even after all his transformations, but I had never heard of him taking a lover, or having any kind of private life at all. His art was everything.

  I followed him, feeling awkward and tongue-tied. Zima led me into the chalet, through an old-fashioned kitchen and an old-fashioned lounge, full of thousand-year-old furniture and ornaments.

  'How was the flight?'

  'Fine.'

  He stopped suddenly and turned to face me. 'I forgot to check . . . did the robot insist that you leave behind your Aide Memoire?'

  'Yes.'

  'Good. It was you I wanted to talk to, Carrie, not some surrogate recording device.'

  'Me?'

  The pewter mask of his face formed a quizzical expression. 'Do you do multi-syllables, or are you still working up to that?'

  'Er . . .'

  'Relax,' he said. 'I'm not here to test you, or humiliate you, or anything like that. This isn't a trap, and you're not in any danger. You'll be back in Venice by midnight.'

  'I'm okay,' I managed. 'Just a bit starstruck.'

  'Well, you shouldn't be. I'm hardly the first celebrity you've met, am I?'

  'Well, no, but--'

  'People find me intimidating,' he said. 'They get over it eventually, and then wonder what all the fuss was about.'

  'Why me?'

  'Because you kept asking nicely,' Zima said.

  'Be serious.'

  'All right. There's a bit more to it than that, although you did ask nicely. I've enjoyed much of your work over the years. People have often trusted you to set the record straight, especially near the ends of their lives.'

  'You talked about retiring, not dying.'

  'Either way, it would still be a withdrawal from public life. Your work has always seemed truthful to me, Carrie. I'm not aware of anyone claiming misrepresentation through your writing.'

  'It happens now and then,' I said. 'That's why I always make sure there's an AM on hand so no one can dispute what was said.'

  'That won't matter with my story,' Zima said.

  I looked at him shrewdly. 'There's something else, isn't there? Some other reason you pulled my name out of the hat.'

  'I'd like to help you,' he said.

  When most people speak about his Blue Period they mean the era of the truly huge murals. By huge I do mean huge. Soon they had become large enough to dwarf buildings and civic spaces, large enough to be visible from orbit. Across the galaxy twenty-kilometre-high sheets of blue towered over private islands or rose from storm-wrecked seas. Expense was never a problem, since Zima had many rival sponsors who competed to host his latest and biggest creation. The panels kept on growing, until they required complex, sloth-tech machinery to hold them aloft against gravity and weather. They pierced the tops of planetary atmospheres, jutting into space. They glowed with their own soft light. They curved around in arcs and fans, so that the viewer's entire visual field was saturated with blue.

  By now Zima was hugely famous, even to people who had no particular interest in art. He was the weird cyborg celebrity who made huge blue structures; the man who never gave interviews or hinted at the private significance of his art.

  But that was a hundred years ago. Zima wasn't even remotely done.

  Eventually the structures became too unwieldy to be hosted on planets. Blithely Zima moved into interplanetary space, forging vast, free-floating sheets of blue ten thousand kilometres across. Now he worked not with brushes and paint, but with fleets of mining robots, tearing apart asteroids to make the raw material for his creations. Now it was entire stellar economies that competed with each other to host Zima's work.

  That was about the time that I renewed my interest in Zima. I attended one of his 'moonwrappings': the enclosure of an entire celestial body in a lidded blue container, like a hat going into a box. Two months later he stained the entire equatorial belt of a gas giant blue, and I had a ringside seat for that as well. Six months later he altered the surface chemistry of a sun-grazing comet so that it daubed a Zima Blue tail across an entire solar system. But I was no closer to a story. I kept asking for an interview and kept being turned down. All I knew was that there had to be more to Zima's obsession with blue than a mere artistic whim. Without an understanding of that obsession, there was no story: just anecdote.

  I didn't do anecdote.

  So I waited, and waited. And then - like millions of others - I heard about Zima's final work of art, and made my way to the fake Venice on Murjek. I wasn't expecting an interview, or any new insights. I just had to be there.

  We stepped through sliding glass doors onto the balcony. Two simple white chairs sat either side of a white table. The table was set with drinks and a bowl of fruit. Beyond the unfenced balcony, arid land sloped steeply away, offering an uninterrupted view of the sea. The water was calm and inviting, with the lowering sun reflected like a silver coin.

  Zima indicated that I should take one of the seats. His hand dithered over two bottles of wine.

  'Red or white, Carrie?'

  I opened my mouth as if to answer him, but nothing came. Normally, in that instant between the question and the response, the AM would have silently directed my choice to one of the two options. Not having the AM's prompt felt like a mental stall in my
thoughts.

  'Red, I think,' Zima said. 'Unless you have strong objections.'

  'It's not that I can't decide these things for myself,' I said.

  Zima poured me a glass of red, then held it up to the sky to inspect its clarity. 'Of course not,' he said.

  'It's just that this is a little strange for me.'

  'It shouldn't be strange,' he said. 'This is the way you lived your life for hundreds of years.'

  'The natural way, you mean?'

  Zima poured himself a glass of the red wine, but instead of drinking it he merely sniffed the bouquet. 'Yes.'

  'But there isn't anything natural about being alive a thousand years after I was born,' I said. 'My organic memory reached saturation point about seven hundred years ago. My head's like a house with too much furniture. Move something in, you have to move something out.'

  'Let's go back to the wine for a moment,' Zima said. 'Normally, you'd have relied on the advice of the AM, wouldn't you?'

  I shrugged. 'Yes.'

  'Would the AM always suggest one of the two possibilities? Always red wine, or always white wine, for instance?'

  'It's not that simplistic,' I said. 'If I had a strong preference for one over the other, then yes, the AM would always recommend one wine over the other. But I don't. I like red wine sometimes and white wine other times. Sometimes I don't want any kind of wine.' I hoped my frustration wasn't obvious. But after the elaborate charade with the blue card, the robot and the conveyor, the last thing I wanted to be discussing with Zima was my own imperfect recall.

  'Then it's random?' he asked. 'The AM would have been just as likely to say red as white?'

  'No, it's not like that either. The AM's been following me around for hundreds of years. It's seen me drink wine a few hundred thousand times, under a few hundred thousand different circumstances. It knows, with a high degree of reliability, what my best choice of wine would be given any set of parameters.'

  'And you follow that advice unquestioningly?'

  I sipped at the red. 'Of course. Wouldn't it be a little childish to go against it just to make a point about free will? After all, I'm more likely to be satisfied with the choice it suggests.'

  'But unless you ignore that suggestion now and then, won't your whole life become a set of predictable responses?'

  'Maybe,' I said. 'But is that so very bad? If I'm happy, what do I care?'

  'I'm not criticising you,' Zima said. He smiled and leaned back in his seat, defusing some of the tension caused by his line of questioning. 'Not many people have an AM these days, do they?'

  'I wouldn't know,' I said.

  'Less than one per cent of the entire galactic population.' Zima sniffed his wine and looked through the glass at the sky. 'Almost everyone else out there has accepted the inevitable.'

  'It takes machines to manage a thousand years of memory. So what?'

  'But a different order of machine,' Zima said. 'Neural implants, fully integrated into the participant's sense of self. Indistinguishable from biological memory. You wouldn't need to query the AM about your choice of wine; you wouldn't need to wait for that confirmatory whisper. You'd just know it.'

  'Where's the difference? I allow my experiences to be recorded by a machine that accompanies me everywhere I go. The machine misses nothing, and it's so efficient at anticipating my queries that I barely have to ask it anything.'

  'The machine is vulnerable.'

  'It's backed up at regular intervals. And it's no more vulnerable than a cluster of implants inside my head. Sorry, but that just isn't a reasonable objection.'

  'You're right, of course. But there's a deeper argument against the AM. It's too perfect. It doesn't know how to distort or forget.'

  'Isn't that the point?'

  'Not exactly. When you recall something - this conversation, perhaps, a hundred years from now - there will be things about it that you misremember. Yet those misremembered details will themselves become part of your memory, gaining solidity and texture with each instance of recall. A thousand years from now, your memory of this conversation might bear little resemblance to reality. Yet you'd swear your recollection was accurate.'

  'But if the AM had accompanied me, I'd have a flawless record of how things really were.'

  'You would,' Zima said. 'But that isn't living memory. It's photography: a mechanical recording process. It freezes out the imagination, leaves no scope for details to be selectively misremembered.' He paused long enough to top off my glass. 'Imagine that on nearly every occasion when you had cause to sit outside on an afternoon like this you had chosen red wine over white, and generally had no reason to regret that choice. But on one occasion, for one reason or another, you were persuaded to choose white - against the judgement of the AM - and it was wonderful. Everything came together magically: the company, the conversation, the late afternoon ambience, the splendid view, the euphoric rush of being slightly drunk. A perfect afternoon turned into a perfect evening.'

  'It might not have had anything to do with my choice of wine,' I said.

  'No,' Zima agreed. 'And the AM certainly wouldn't attach any significance to that one happy combination of circumstances. A single deviation wouldn't affect its predictive model to any significant degree. It would still say "red wine" the next time you asked.'

  I felt an uncomfortable tingle of understanding. 'But human memory wouldn't work that way.'

  'No. It would latch on to that one exception and attach undue significance to it. It would amplify the attractive parts of the memory of that afternoon and suppress the less pleasant parts: the fly that kept buzzing in your face, your anxiety about catching the boat home and the birthday present you knew you had to buy in the morning. All you'd remember was that golden glow of well-being. The next time, you might well choose white, and the time after. An entire pattern of behaviour would have been altered by one instance of deviation. The AM would never tolerate that. You'd have to go against its advice many, many times before it grudgingly updated its model and started suggesting white rather than red.'

  'All right,' I said, still wishing we could talk about Zima rather than me. 'But what practical difference does it make whether the artificial memory is inside my head or outside?'

  'All the difference in the world,' Zima said. 'The memories stored in the AM are fixed for eternity. You can query it as often as you like, but it will never enhance or omit a single detail. But the implants work differently. They're designed to integrate seamlessly with biological memory, to the point where the recipient can't tell the difference. For that very reason they're necessarily plastic, malleable, subject to error and distortion.'

  'Fallible,' I said.

  'But without fallibility there is no art. And without art there is no truth.'

  'Fallibility leads to truth? That's a good one.'

  'I mean truth in the higher, metaphoric sense. That golden afternoon? That was the truth. Remembering the fly wouldn't have added to it in any material sense. It would have detracted from it.'

  'There was no afternoon, there was no fly,' I said. Finally, my patience had reached breaking point. 'Look, I'm grateful to have been invited here. But I thought there might be a little more to this than a lecture about the way I choose to manage my own memories.'

  'Actually,' Zima said, 'there was a point to this after all. And it is about me, but it's also about you.' He put down the glass. 'Shall we take a little walk? I'd like to show you the swimming pool.'

  'The sun hasn't gone down yet,' I said.

  Zima smiled. 'There'll always be another one.'

  He took me on a different route through the house, leaving by a different door than the one we'd come in by. A meandering path climbed gradually between white stone walls, bathed now in gold from the lowering sun. Presently we reached the flat plateau I'd seen on my approach in the conveyor. The things I'd thought were viewing stands were exactly that: terraced structures about thirty metres high, with staircases at the back leading to the different levels. Zima
led me into the darkening shadow under the nearest stand, then through a private door that opened into the enclosed area. The blue panel I'd seen during the approach turned out to be a modest rectangular swimming pool, drained of water.

  Zima led me to the edge.

  'A swimming pool,' I said. 'You weren't kidding. Is this what the stands are all about?'

  'This is where it will happen,' Zima said. 'The unveiling of my final work of art, and my retirement from public life.'

  The pool wasn't quite finished. In the far corner, a small, yellow robot glued ceramic tiles into place. The part near us was fully tiled, but I couldn't help noticing that the tiles were chipped and cracked in places. The afternoon light made it hard to be sure - we were in deep shadow now - but their colour looked to be very close to Zima Blue.