'They all failed—'

'By luck only, chief. The hospital food - I think you didn't eat it, but one of the cooks did. The meteorite -'

'Odd attempts. Inefficient, too.' He thought for a moment, and then packed the memory sword that Korodore had given him. As he turned, his eye caught the pink cube resting on the cubecase. Hrsh-Hgn's Joker thesis. He packed it.

'I'm not safe here, that's for sure. We leave now, while it's still night.'

'If you try and fly you'll fry. Samhedi's got the force screens up around the walls. We could try walking out. You'll have to order me to use necessary force, though.'

'Right,' said Dom.

'In full, please. If the fuzz get me afterwards, it'll all be down on my recorders. Can't disassemble a robot for obeying orders: Eleventh Law of Robotics, Clause C, As Amended,' said the robot firmly.

'Then get me out of here, using no more force than is necessary.'

The robot walked over to the door and called in the security man who was standing guard down the corridor. Then he pole-axed him.

'Not bad,' he said. 'Enough to stun but not enough to shatter. Let's split, boss.'

The buruku was built on the outskirts of the city, where the dry land sloped towards the marsh. It looked like a field of mushrooms under a grey dome. Each mushroom was a reed-woven rath, some of them several times larger than a human geodome. The grey dome was the low-degree force screen, just powerful enough to keep the atmosphere within damp and still. It was polarized too, so that the light that filtered through was dim and subterranean. Inside the air was warm, clammy and smelled of decay .Dom felt that if he breathed deeply horrible moulds would sprout in his lungs. It was what ten thousand phnobes called home.

Towards the centre of the colony the raths huddled together in a fungal township riddled with alleyways and sprouting several distressingly organic-looking towers and civic buildings. Shops were still open, though it was well past midnight; they mostly sold badly-dried fungi, fish or second-hand cubes. From some of the larger raths, bulbous as fermenting pumpkins, came snatches of haunting chlong music. And all around Dom phnobes filled the streets.

In a purely human environment a solitary phnobe looked either pathetic or disgusting, from its goggled eyes to the slap of its damp feet on the floor. In the rath they loomed like ghosts, self-assured and frightening. Most of the alpha-males carried long double-bladed daggers, and any visitor with a concealed inclination towards shape-hatred ended up walking with his back pressed firmly against a comfortingly solid wall.

At one point they had to press into the crowd as a wicker-work delivery truck trundled by. It stank: it was powered by a ceramic engine fuelled with fish oil.

A nd the air was filled with hissing, a susurration like the wind, the sound of phnobic speech. Dom enjoyed the buruku. The phnobes had a way of life divorced entirely from the carefully stylized penury of a Sadhimist ruling family.

Dom found Hrsh-Hgn seated in a communa l ja s ca, playing tstame. He glanced up at the two of them, and waved them into silence.

Dom sat down on the stone seat and waited patiently. Hrsh-Hgn's opponent was a young alpha-male, who looked at Dom disinterestedly before turning back to the board.

The tstame men were crude and badly co-ordinated, which was to be expected from a public set. Even so, they were being directed across the squares with a gawky grace.

Red's pawns had dug a defensive trench across one corner of the board. White had tried the same tactic, but had stopped work and the pawns were clustered around one of Red's knights, who was haranguing them. As Dom watched, Red's Sacerdote-Shaman brought his mitrepike down on the kill-button of White's Accountant, and in the ensuing melee managed to get several pawns through the crossfire from the Rooks. The King made a brave attempt to run for it but was brought down by a flying tackle from the leading pawn.

Hrsh-Hgn's opponent removed his helmet and made a grudgingly complimentary comment in phnobic before loping away. Dom's tutor turned.

'I want you to help me find Joker's World,' said Dom.

He explained.

The phnobe listened politely. At one point he said: 'I'd be interessted to know how you survived a black hole that removed Korodore.'

'Yes, and Ig.'

'But no, that is not sso ...' He reached down beside him and picked up a wicker cage. Inside, Ig fizzled.

'I found him in the busshess at the edge of the lawn. He was badly sshaken. He must have left your sshoulder somehow.'

'And you looked after him - that's surprising, for you.'

Hrsh-Hgn shrugged. 'No one elsse would. The fisshermen are supersstitious of them. They ssay they are the ssouls of dead comrades. '

The swamp creature looped itself around Dom's neck.

'Are you coming with me... us?'

'Yess, I think sso. I accept bater.'

'I never did find out what that word meant.'

'It refers to the inexorable processesss of what you humans are pleased to call Fate. Where did you think of starting? Don't look so blank.'

'It's just that I expected a lecture on my duties as Chairman. As my tutor you were hot on the subject, I seem to remember.'

The phnobe smiled, switched his headset on and turned to the board. The tstame mannikins stood up, ranged themselves into two neat rows, and marched down a flight of steps that appeared in one of the neutral squares, carrying the temporarily disabled.

'The point doess not arise now,' he said, 'Ass a mere frog' - he looked sharply at Isaac - 'I suggesst you follow the path predicted. Bessides, ass a Joker student of ssome repute, and an amateur probability mathematician to boot, I feel intrigued. Tell me, are you embarking upon thiss because it hass been seen to happen in the future, or has it been seen to happen in the future because you are following the prediction now?'

'I don't know,' said Dom, 'But I know where there's a ship—'

'Mr Chairman!'

Impressions crowded in on him. The low-ceilinged room had gone quiet, suddenly, like the switching off of a music cube, leaving the sort of silence that is even louder and hangs in the air like fog. The players bent over the tstame tables did not move, but now they seemed tense.

The chlong trio stopped playing. Ig whined.

Samhedi stood in the doorway, flanked by two minor security men. And they were armed. Dom remembered Korodore's advice, one day when the dead man was feeling expansive, that only the foolhardy or unimaginative carried projectile weapons into a buruku. Korodore had in fact hefted a regulation double-bladed knife, and then diffidently, on the rare occasions he went in.

'We have come to escort you home, Mr Chairman.'

Dom strode towards him and said politely, too politely: 'You were number two on Terra Novae, weren't you?'

'I was.'

'Who told you to carry stunners into a buruku ?'

Samhedi swallowed, and glanced sidelong at the guards. The room seemed to sprout ears.

'Your predecessor would not have done such a thing. You might just have precipitated an inter-racial incident. Now unbuckle those things and throw them on the floor.'

'I have orders to see you safely home—' began Samhedi.

'From my grandmother? She has no authority. What law am I breaking? But you're breaking phnobic custom—'

He had driven the man too far. Samhedi growled.

'What gecky customs do these frogs have, anyway?'

He said it in bad phnobic. One by one the phnobes stood up, tshuri knives glinting in the deep gloom.

The alpha-male that had played tstame with Hrsh-Hgn loped up to Samhedi and threw his knife into the floor between them. Samhedi looked at Dom.