Marco hissed and struck out at another machine that was trying to climb up his leg. It landed on its back, scrabbling at the deck with all six arms.

Kin laughed hysterically.

'Don't be childish' she gasped. 'When we flip into interspace you'd like to be in a contour-couch, wouldn't you? All they want are your measurements. DO IT!'

Marco opened his mouth to protest, and something touched his face. Looking down, he saw a metal tape unrolling on its way to the deck. He looked up. A robot was dangling above his head. He sighed.

The ship rose into daylight. It emerged in the middle of a black sand beach, with the copper dome of the hub behind it. The sea moved lazily a few metres away. There was a shudder as the lift platform locked.

Now the cubes were spraying foam over three structures of curved tubing which they had bolted to the floor. The foam congealed into about the right sized hollows for a shand, a kung and a human.

'We've got a little time until lift-off,' said Kin, and stood up. 'Has anybody got any questions? Yeah. I thought you might. OK, but get in the couches.'

'You don't expect me to get us into interspace from the disc surface?' asked Marco. 'We wouldn't have a chance!'

'You did it from Kung' said Kin, settling into her couch.

'Kung hasn't got a damn great dome over the sky!'

'No. I don't expect to flip yet, anyway. We need the couches for the primary launch.'

'But who is going to be at the controls? I can't reach them from here!'

'No-one is going to be at the controls. There aren't any for the launch. Trust me.'

'No controls and you want me to trust you?'

'Yes. I want you to trust me.'

Marco lay down and reached for the couch straps. Silver was already prone. They lay in silence for a while.

Then Kin said, 'Marco, can you see that round screen from your couch?'

'I see it.'

'It's radar. Keep an eye on it. And now, perhaps I owe you an explanation...'

HELP, said the screen.

Trying not to think about it, Kin lifted the occupant out of the chair, and sat down in front of the pleading letters. Keeping the hovering helmet in the top of her eye, she ran her hand over the arm.

Nothing happened, except that the screen now read

YOU ARE KIN ARAD.

'That's--' Kin's voice sounded faint in the closeness of the room. She cleared her throat. 'That is correct,' she said. 'Who are you?'

WE BELIEVE YOU HAVE REFERRED TO US AS THE DISC MASTERS, ALTHOUGH WE CALL OURSELVES THE COMMITTEE.

'It's got a nice democratic ring about it. Let me see you.'

IS THAT AN EXPRESS WISH?

'Well, I've come a long way to meet you. This is hardly an intimate conversation, you must admit.' Kin looked around; looking for doors, hidden cameras. The walls were blank.

YOU MISUNDERSTAND US, WE ARE MACHINES. COMPUTERS, JAGO JALO CALLED US. WE FAIL TO UNDERSTAND YOUR SURPRISE.

'I'm not surprised,' lied Kin.

THEN WE SUGGEST YOU SUE YOUR FACE FOR SLANDER.

'Why do you need help? It's me that needs help. What has happened to my friends?'

THEY ARE SAFELY IN PROTECTIVE CUSTODY. THEY WERE TOO VIOLENT TO BE ALLOWED TO ROAM LOOSE, OF COURSE. DO YOU WISH THEM TO BE FREED, AND FOR US TO PROVIDE YOU WITH TRANSPORT TO YOUR HOME WORLD? IF YOU SO ORDER, IT WILL BE DONE.

'I can order you?'

YOU SIT IN THE CHAIR. THERE IS NO OTHER INCUMBENT. YOU ARE THE CHAIRMAN. THEREFORE YOU CAN GIVE THE ORDERS. WE IMPLORE YOU TO DO SO.

'You can build me a ship?'

WE BUILT A SHIP FOR JAGO JALO. WE ASISSTED HIM, DESPITE ALL THAT HE DID. CHOICE DOES NOT EXIST FOR MACHINES IN MATTERS OF THIS NATURE. JALO CHOSE TO FLEE THE DISC RATHER THAN LEARN MORE ABOUT IT.

Kin considered this carefully. When she spoke, she spoke slowly.

'You will give me a ship, but if I chose to leave the disc you won't tell me any more about it?'

YES.

'But you said I could give the orders.'

YES. HOWEVER, WE BELIEVE WE WILL SHORTLY EXPERIENCE A SLIGHT MALFUNCTION IN OUR AUDITORY CIRCUITRY. IT MAY PREVENT US FROM HEARING ANY SUBSEQUENT ORDERS.

Kin smiled. 'Then there's no choice, is there? Not against blackmail. Tell me about the disc.'

'Kin' said Marco urgently. 'There's something on the screen.'

'It's about time,' replied Kin. 'Don't worry.'

'Yeah, I remember. Trust you. It's bloody big. What is it?'

'It's our launch vehicle.'

Kin leaned back in the oh-so-easy chair and stared at the blank screen for a long time.

'You're wearing out' she said. 'That's why the seas are going mad and the climate's shifting. I understand that. The disc is a machine. Machines have a finite life. That's why the Company builds planets.'

PLANETS HAVE A FINITE LIFE.

'A longer one. They don't start to squeak on their bearings after half a million years.'

YOU GLOAT?

'No. I keep thinking of a few hundred million people on a spaceship the size of a world, and then I think of all the things that can go wrong with a ship. I don't gloat, I tremble with fear. And rage.'

She stood up and stomped across the room to ease the cramp in her muscles. It had been a long session, a subterranean travelogue of disc machinery. The earthquake machines stuck in her memory. All that ingenuity, to reproduce what any half-sized world did naturally. And the demons... well, at least she'd put a stop to the demons.

There was a click as Marco undid his straps and leapt towards the horseshoe panel. He peered at the screen, then glared out of the cabin.

'Where the hell is it? It's gone off the screen. What was it, Kin? The blip was bigger than a--'

Whump. Beyond the windows the seashore exploded into a sandstorm.

Marco craned his head and looked up. Darkness filled the cabin as the sun was eclipsed.

Whump.

Marco looked up at talons dropping out of the sky when the impossible bird stooped. Talons big enough to grip a ship. He made a small noise in his throat and took a dive in the direction of his couch.

Whump. Scrabble. Whump. Whumpwhump. Whumpwhump.

The ship creaked as the claws took it gently. Then it bounded upward in a series of boneshaking jerks.

The dome of the hub swung crazily below, and whirled away. The disc dropped after it, teetering across the sky until it was a blue and ochre wall. It paused there, then plunged back under the ship to loom for a moment on the other side. Whump.

Kin concentrated on the view above, to take her mind off the lurching, jerking universe. The talons all but covered the roof port, but she got occasional glimpses of the huge white wings, beating now with the slow rhythm of a tide.

Sound filled the cabin. It began in the painful ultrasonic, swooping down the scale like wet fingers being dragged across the windows of the soul.

High above the disc the roc stood on the air and sang.

There would be no more demons. She could see why there had been demons, demons were an idea that worked, but there would be no more.

The ones Kin had met had been almost human compared with some of the things force-bred in the quiet green laboratories under the hub. They policed the disc, haunted the hidden air vents and access shafts to the machinery, chased the venturesome from the rim. Occasionally they kidnapped a new Chairman, for the Committee.

The Chairmen. Kin stared at the blank screen, then glanced up at the hovering direct-link helmet over the chair. She had no intention of trying it for size, and the Computers hadn't pressed her, but they had shown her how it was used.

The Computers ran the disc. They adjusted its tides, circulated its waters, counted its falling sparrows, toiled and spun for the lilies of its fields. But the disc's builders had constructed them as servile mechanisms, lest the disc become too mechanical. A human had to tell them what to do.

In the 70,000 years of the disc's history there had been 280 Chairmen, thrust in terror under the helmet. It gave them cold new knowledge.