'This is the brain of the building. If you could say this place has got a brain. Operates the elevators, sniffs for fires, checks ID cards. It chews mine up about twice a year. Big expensive system but not exactly what you'd call smart. A lot of bespoke software, communications, security, maintenance, stuck together over the years.

'It controls the sprinklers?'

'The sprinklers, the cameras. All the doors and windows. Here's the interesting bit. Central or backslash Cen, or Big Ken to his friends also has to interface with all the company networks in the building. If you've got offices here your computers have to talk to Big Ken. If there was a fire or something the Central has to know where everybody is, who's logged in at what location. Figure out optimal escape routes for everybody in the building.'

'It draws vectors,' said the Doctor, thinking aloud. 'Or it deals with it as a problem in topology.'

'It probably uses voodoo,' said Maria. 'This thing is so old it used to have a command line you typed on. Remember those?'

'But you can access any data in the building through this route.'

'Absolutely. And not only access. Big Ken has to be able to slot an evacuation message across their screens. So Central can preempt any process that's running on any computer in the building.'

The Doctor smiled.

'Took me years to learn my way around. I know it pretty good by now.' Maria flexed her fingers over the keyboards. 'Central also controls a lot of the cleaning hardware. Stuff I have to operate. Maintains the schedules. Reminds me when the air conditioning ducts need doing and helps me route the scrubbers. Don't want any of that legionnaire virus floating around.'

The Doctor reached over her shoulder and punched some b.u.t.tons on the keyboard. The office directory appeared on the screen, listing all the companies who leased s.p.a.ce in the King Building. From Amoco to Zenith. Polychrome logos and badges flashed up beside some of the names. You could tell how well a company was weathering the corporate storm by the sophistication and expense of its computer graphics.

'How long have you worked in this building?' The cat was beside the Doctor now, looking at the screen. Maria had noticed that before with cats. They were interested in what you were interested in.

'Forever,' she said.

'That's a very long time. Always for the Butler Inst.i.tute?'

'No. Anywhere in the building. I cleaned for other companies plenty of times.'

'But who pays you? Always the Butler Inst.i.tute?'

'Yes.'

The Doctor was smiling again, but something was different this time. 'Does that suggest anything to you?' He was looking directly at her now. The light of the screen was reflected in his eyes. Like two tiny screens looking out at her, full of data she'd never be able to read.

'Tell me something. Why am I helping you?'

'Perhaps because you know what the Butler Inst.i.tute is. And perhaps you can see what it will become. Can you get at their current projects directory?'

'That's highly cla.s.sified stuff.'

'Can you get at it?'

'No problem.'

As she typed, Maria realized that she was making a noise. Low and rhythmic. She was singing to herself. It took her a few moments to place the song. Something by The Clash.

The system security had been improved since the last time Maria had hacked into the Butler Inst.i.tute records. That had been at Christmas, to authorize a bonus for herself. Nothing too flashy, nothing that would get noticed. She'd earned it, cleaning up the wreckage after the office party. The workstation had had a sprig of mistletoe fixed over its screen and it had taken her about fifteen minutes. This took her an hour and a half, and all she found were some personnel records. Details of two cops called Mancuso and McIlveen. When the stuff flashed up on the screen, the Doctor smiled. 'Just confirming a theory,' he said. He retreated through levels of memory, closing each window down as he went. It was like retreating through a series of Chinese boxes. Sometimes he pulled down menus and ran through random processes. Maria knew what he was doing. He was removing his traces, hiding his route from the auditing software. Like brushing leaves over your footprints in a forest. When he was finished he switched the computer down, and picked up a pen and a pad of paper from the adjacent desk. 'Do you think anyone will mind if I borrow these?' he said, smiling at Maria.

They were alone in the corridor except for the vacuum units, travelling over the carpeting and in and out of the offices. The Doctor was walking, moving very quickly, but Maria wasn't having any trouble keeping up with him. She hadn't felt like this in years. 'Is that it?' she said.

'For now,' said the Doctor. 'I've got what I came for.'

'So what happens next?'

'I have to travel to certain places and meet certain people.'

'Are you coming back?'

'I'm far from finished here,' said the Doctor. He turned and looked back down the corridor. Two tiny lights shone in the darkness, moving. The cat came trotting out of the shadows and joined them. The Doctor looked at Maria. 'Thank you for your help.' He picked the cat up and turned away, moving down the corridor. Maria stood and watched him. When she opened her mouth she intended only to speak the words, but they came out as a shout.

'Take me with you.'

The Doctor stopped. He turned and looked at her. The cat wriggled out of his arms and dropped to the carpet. It walked off around the corner.

'No,' said the Doctor.

'Why not?' Maria moved down the corridor, closer to the Doctor.

'Because of 51,' said the Doctor.

'What?' Maria's voice was shaking. She could hear it herself.

'The fiftyfirst floor in this building. You know what goes on there.'

'No.'

'Yes. You've known for years, and you've let it happen.' The Doctor turned away from her and walked around the corner, after the cat.

Maria didn't try to follow him.

There was a blast of blue light, like a giant taking a photograph, a sound she couldn't describe, then a rush of air. An indoor wind, gusting past her from behind, rushing around the corner, sucking dust from the carpet. Too long since that carpet was vacuumed, she thought numbly. After a moment she made herself look around the corner. There was nothing there, of course.

It was about seven o'clock when Maria got home that morning. She found a s.p.a.ce for her Toyota, pulled in and switched off the car. It wasn't until she tried to get out of the car that she realized something was wrong. She first noticed it in her hands as she reached for the door handle.

Shaking.

And it was as if noticing it made it worse. Now her hand shook uncontrollably. She pulled it in, tight to her body. Now her body began to shake, too. The tremors began hitting her in waves. Her legs as well. Maria looked out the window, wondering if it was an earthquake, but the storefronts and the pa.s.sing cars remained steady.

Anyway, this wasn't earthquake country. This wasn't home. Was it? Outside the car were palm trees and hot blue sky shining through a moving film of fumes. Maria could feel the warmth through the gla.s.s of the window. She moved her hand to the b.u.t.ton to open the car window. She wanted to open the window and feel the summer heat rush in on her, breathe the sweet hot tarry air.

Breathe.

Maria took a breath and found she couldn't get any air at all. Her hand was twitching feebly on the car seat. She tried to move to the window b.u.t.ton but her hand just lay there.

But it didn't matter.

It didn't matter that her body was shaking like this. There was something familiar about the shaking. The shaking and the rhythm and the heat. Her mind was growing more remote but she could still recognize the rhythm and the heat.

Maria stopped fighting it.

She let herself go. Lost herself in the trembling of her body. She didn't feel any fear. The music kept the fear away. A steady pounding, echoing off concrete walls. She let her body follow the beat of the music. The warmth washed over her, the beersweatandbas.e.m.e.nt smell.

As she went she started losing everything.

Jerome went. The sunlight on her face went. Joss stick smoke curling past a paintstained wall. Warmth of the bong in her hand.

It didn't matter.

She was dancing.

4.

They were about five blocks behind him by the time he reached the munic.i.p.al library on Wendacott Avenue.

They'd been chasing Bobby Prescott for half an hour now and his batteries were running low. He used the last of the power to put on a burst of speed as he came round the corner by the mall, past Smartt Software and McCray's drugstore.

Even now Bobby Prescott felt something as he pa.s.sed McCray's. He s.n.a.t.c.hed a glance back. The streets were still clear. He looked around, taking in the familiar neighbourhood terrain. He found himself unconsciously trying not to look at McCray's. So he forced himself to stare at the place. He was pa.s.sing near an outside corner of the mall facing Wendacott. McCray's was ahead and to the left. It was just an old drugstore with some cars out front.

Bobby Prescott shot past McCray's and the Seven Eleven, then he cut across the empty street and up on to the sidewalk, outside the library grounds. The changing texture of concrete caused his wheels to buzz. Spotlights blazed on poles in the empty tarmacked ap.r.o.n outside the library. Their light caused the steel bars of the library fence to strobe as he swept past. The open front gate of the library was coming up now. Bobby Prescott calculated, counting, and then he leaned outwards and grabbed at a streetlamp. He curved his leathergloved hand around it, gripping and pulling hard.

At the speed he was travelling the manoeuvre bruised the flat of his hand and wrenched the muscles of his shoulder. But it also sent him rocketing off on a rightangle turn and straight into the library grounds without noticeably reducing his speed.

The plastic wheels of his roller skates made a gunshot sound as he crossed a narrow steel groove in the road surface. The heavy steel mechanism of the library gates had once run in this gutter, keeping the gates in alignment as they rumbled shut.

Bobby Prescott glanced back over his shoulder again. Still nothing. Just the quiet street and the open gates. Those gates had been jammed permanently open ever since the riots twenty years ago. Some grade 12 kids had taken steel bars out of the shop storeroom at their school and done the business with them, putting paid to the riot barrier by feeding the big metal bars into the cogged wheels. The wheels had churned and screamed and splintered.

Bobby Prescott had almost lost his hand that day. He hadn't let go when the gate began to chew up one of those bars.

Now he cut the power to his skates and coasted the last twenty metres, angling his skates slightly to kill the last of his momentum as he reached the bottom of the wide concrete steps of the library. The first bicycle would be coming past the mall on Wendacott, coming past Smartt's and McCray's and the Seven Eleven about now. Bobby Prescott sat down on the bottom step and rested for a moment. He looked at the sprayed and carved graffiti around him and took comfort in it.

This was as good a place as any.

Unlacing the roller skates took maybe four seconds. In the distance Bobby Prescott could hear the skimming of bicycle rubber on the street surface, approaching fast. When he had the skates off he packed them in his rucksack, leaving the top of the sack open for quick access.

The first bicycle was coming up the school entrance now, rattling as it crossed the gate gutter, the kid on the bicycle coming through the dark places between the school spotlights. Ghost white face and T-shirt swimming across the shadows, coming straight towards Bobby Prescott. The kid was very confident. Some sort of long knife was attached with clips along the main axis of the kid's bike. The kid was reaching down to unclip it. He was eager. Bobby Prescott recognized him. This kid had consistently led the pack for the past hour as they hunted him down.

But Bobby Prescott recognized the kid in another way, too. It was like looking at himself, twenty years ago.

The kid let his bicycle drop on to the ground and jumped clear of it, running for the steps where Bobby Prescott sat, knife held out to one side. Bobby Prescott strung the rucksack across his shoulder and clipped a security strap to the belt of his jeans. On the left of the belt was a battery pack like the ones kids used for their personal stereos. Bobby Prescott used it to power his skates. On the right of the belt, balancing the battery pack, he had a sealed length of heavy flexible black plastic, ribbed for easy grip and filled with lead shot. It was called a sinker. The sinker made a heavy wet sound as it connected with the bicycle kid's head. The kid dropped the knife and fell over, twitching, and Bobby Prescott picked the knife up and went over to the bike, lying there on the tarmac.

The front wheel was still spinning, a black plastic badge shaped like a bird's head rotating on the spokes. Bobby Prescott hesitated, not wanting to touch the bicycle. He was thinking about McCray's drugstore and what had happened there. He made himself touch the bicycle. He bent close, using the knife on the bike's mudguard, ruining the fine German edge on the blade. It was a shame, but Bobby Prescott needed a weapon with a decent reach.

The main pack of bicycle kids would be coming past the Seven Eleven by now. Bobby Prescott stayed calm and used the long thin knife to free the bicycle chain. He swept its oily length back and forth in the air a few times, judging the weight of it.

The rest of them were in sight now. The bicycle kids or whatever the gangs called themselves these days. Gameboys. Witchkids. Crows. Bobby Prescott had lost track.

He watched them as they came through the school gate. Two of them side by side, then three more in single file. Crows, that's what this gang called themselves. The wheel on the fallen bicycle was clicking to a halt now and the bright red eye on the crow'shead badge steadied and glinted up at Bobby Prescott.

A final straggler coasted into the library parking lot, the spotlights making the shadow of his bicycle huge and skeletal on the ground. A memory tried to force itself into Bobby Prescott's mind, the same memory that had made him flinch when he touched the bicycle. He looked up and saw the illuminated sign on McCray's drugstore glowing on the other side of the road. Bobby Prescott concentrated and forced himself to look away, back at the bicycle kids. It would be different this time.

He took a deep breath and prepared himself for what was coming.

The straggler made it a total of seven of the kids, if you counted the one lying bleeding by the steps. They ranged from about twelve to fifteen in age.

It took five of them to bring Bobby Prescott down.

He never really got to use the bicycle chain properly. It dropped from his hand as the youngest kid stomped his fist. The sixth one was waking now, shaking his head and moaning and throwing up as he came back to consciousness. The seventh one, the straggler, had picked up the German knife and was coming forward, getting closer, face tense and frowning with excitement. Bobby Prescott was thinking calmly and quickly, going through the options. The edge of that knife was dulled now but that wouldn't buy him any time. The kid wouldn't need the edge of it.

He was close now, looking down at Bobby Prescott. The kid was wearing a bicycle helmet that had been modified to look like a gaming helmet, with VR decals on it. That was all part of the stuff Bobby Prescott would never understand about these kids. The VR games and the bicycles and the way they hated anything that was a machine or used power. Unless of course it was one of the computers that they needed for their games.

The knife was coming close now, getting big as it neared his face. Bobby Prescott noted that the blade looked clean and for some absurd reason he was relieved. He concentrated on the brightly coloured gaming stickers as the knife's tip pressed against his throat. He didn't look at the eyes of the kid, he wasn't going to give him that satisfaction. Bobby Prescott let himself go limp. He was going to die and he knew it. He felt the fear starting in him but it was just his body, glands feeding the bloodstream. Just the animal in him. Bobby Prescott had to put that animal down. Bobby Prescott had been fighting on the streets for nearly thirty years. He'd used a knife himself. He'd killed people himself. Now there was one last fight for him to carry out. Not against the kids who held him. They were young and strong. Sweating with excitement. There was no victory there.

But Bobby Prescott was going to have a victory. He was going to win a last fight. He readied himself, to confront the fear. He began to fight the fear.

He could feel himself winning already. The kid was close now. Freckles on his pale face, a ring of acne around his mouth. Little wispy moustache. The knife was beginning to enter Bobby Prescott's throat but all he felt was a warm flash of pleasure. He'd applied his willpower and he already knew that he was going to win. His breathing was beginning to ease already and his body, pressed against the hard edges of the library steps, eased too.

He relaxed, drifted away.

The fear flared one last time.

Died.

Now Bobby Prescott wasn't afraid of anything. He was grinning with satisfaction as the tip of the knife slowly cut into him, the kid holding the knife getting excited but beginning to get into it, his hand steady. He was going to really go for it any second and drive the blade right in. Bobby Prescott just grinned up at the kid as the kid began to kill him.

'That's enough,' said the small man.

Bobby Prescott had been aware of the small man for some time, standing there at the edge of his vision, but he had dismissed him as an irrelevant piece of phenomenon, background noise. The important thing had been Bobby Prescott's last fight. But now the kids holding him were loosening their grip, letting go at the man's command.

Bobby Prescott's concentration began to unlock. His mind began to come back from the deathplace he'd prepared for it. The knife was moving away from him, coming back out of his throat, blood on the tip of it, the kid's hand still tight around the handle, reluctant. But moving. Bobby Prescott began to let himself think again. His memory unfroze and he could remember that the small man had come out of the gla.s.s doors and down the steps towards them. He had come out of the library, just a small man holding a big black envelope in one hand.

And now he was giving them orders, the kids, the Crows. Giving them orders and moving his hands, the envelope jabbing as he spoke. And the kids, the little animals with their bicycles and their helmets and knives, were obeying him.

The smell of the books. .h.i.t Bobby Prescott even before his eves adjusted to the darkness. 'I'm afraid the lights are dead in here,' said the small man, walking somewhere in the shadows just in front of him.

'They're dead everywhere in the library. They have been for a long time,' said Bobby Prescott. 'Years. Ever since the big riots.' He could see now. There was enough light coming in from the tall library windows to make out the wreckage of the front desks, the shelves which had once held the latest magazines. The disembowelled overturned shape of a Xerox machine. But Bobby Prescott could have closed his eyes and still found his way through here. The smell of the books brought it all back to him.

He remembered the first time he'd ever come into this library, with the man he'd called Uncle Max. Uncle Max was there on business, looking up something to do with human anatomy, and he'd let Bobby wander off. The little boy had seen a book on a shelf, too high for him to reach, and a lady, one of the librarians, had fetched it down for him. It was the first book Bobby Prescott ever read. He couldn't remember the t.i.tle, but he could still close his eyes and see the cover, and he could tell you the story.