'How did you know that?'

'An Igor learnth to antithipate, thur,' said Igor. 'What a wonderful little kitchen, thur. I've never theen a drawer marked 'Thpoonth' which jutht hath thpoonth in it.'

'Are you any good at working with glass, Igor?' said Jeremy, ignoring this. 'No, thur,' said Igor, buttering the toast. 'You're not?'

'No, thur. I am bloody amathing at it, thur. Many marthterth have needed... thpethial apparatuth not obtainable elthewhere, thur. What wath it you wanted?'

'How would we go about building this?' Jeremy spread the sheet on the table. The slice of toast dropped from Igors black-nailed fingers. 'Is there something wrong?' said Jeremy. 'I thought thomeone wath walking over my grave, thur,' said Igor, still looking shocked. 'Er, you haven't actually ever had a grave, have you?' said Jeremy. 'Jutht a figure of thpeech, thur, jutht a figure of thpeech,' said Igor, looking hurt. 'This is an idea I've ...I've had for a clock...'

'The Glath Clock,' said Igor. 'Yeth. I know about it. My grandfather Igor helped build the firtht one.'

'The first one? But it's just a story for children! And I dreamed about it, and-'

'Grandfather Igor alwayth thaid there wath thomething very thtrange about all that,' said Igor. 'The ecthplothion and everything.'

'It exploded? Because of the metal spring?'

'Not ecthactly an ecthplothion,' said Igor. 'We're no thtrangerth to ecthplothionth, uth Igorth. It wath ... very odd. And we're no thtrangerth to odd, either.'

'Are you telling me it really existed?' Igor seemed embarrassed about this. 'Yeth,' he said, 'and then again, no.'

'Things either exist or they don't,' said Jeremy. 'I am very clear about that. I have medicine.'

'It ecthithted,' said Igor, 'and then, after it did, it never had. Thith ith what my grandfather told me, and he built that clock with thethe very handth!' Jeremy looked down. Igor's hands were gnarled, and, now he came to look at them, had a lot of scar tissue around the wrists. 'We really believe in heirloomth in our family,' said Igor, catching his gaze. 'Sort of... hand-me-downs, ahahaha,' said Jeremy. He wondered where his medicine was. 'Very droll, thur,' said Igor. 'But Grandfather Igor alwayth thaid that afterwardth it wath like... a dream, thur.'

'A dream...'

'The workthop wath different. The clock wathn't there. Demented Doctor Wingle, that wath hith marthter at the time, wathn't working on the glath clock at all but on a way of ecthtracting thunthine from orangeth. Thingth were different and they alwayth had been, thur. Like it had never happened.'

'But it turned up in a book for children!'

'Yeth, thur. Bit of a conundrum, thur.' Jeremy stared at the sheet with its burden of scribbles. An accurate clock. That's all it was. A clock that'd make all other clocks unnecessary, Lady LeJean had said. Building a clock like that would mean the clockmaker went down in timekeeping history. True, the book had said that Time had got trapped in the clock, but Jeremy had no interest whatsoever in things that were Made Up. Anyway, a clock just measured. Distance didn't get tangled up in a tape measure. All a clock did was count teeth on a wheel. Or... light... Light with teeth. He'd seen that in the dream. Light not as something bright in the sky, but as an excited line, going up and down like a wave. 'Could you... build something like this?' he said. Igor looked at the drawings again. 'Yeth,' he said, nodding. Then he pointed to several large glass containers around the drawing of the central column of the clock. 'And I know what thethe are,' he said. 'In my dr- I mean, I imagined them as fizzing,' said Jeremy. 'Very, very thecret knowledge, thothe jarth,' said Igor, carefully ignoring the question. 'Can you get copper rodth here, thur?'

'In Ankh-Morpork? Easily.'

'And thinc?'

'Lots of it, yes.'

'Thulphuric athid?'

'By the carboy, yes.'

'I mutht have died and gone to heaven,' said Igor. ' Jutht put me near enough copper and thinc and athid, thur,' he said, 'and then we thall thee thparkth.' Tick 'My name,' said Lu-Tze, leaning on his broom as the irate ting raised a hand, 'is Lu-Tze.' The dojo went silent. The attacker paused in mid-bellow. '-Ai! Hao-gng! Gnh? Ohsheeeeeeohsheeeeeee ...' The man did not move but seemed instead to turn in on himself, sagging from the martial stance into a kind of horrified, penitent crouch. Lu-Tze bent over and struck a match on his unprotesting chin. 'What's your name, lad?' he said, lighting his ragged cigarette. 'His name is mud, Lu-Tze,' said the dojo master, striding forward. He gave the unmoving challenger a kick. 'Well, Mud, you know the rules. Face the man you have challenged, or give up the belt.' The figure remained very still for a moment, and then cautiously, in a manner almost theatrically designed not to give offence, started to fumble with his belt. 'No, no, we don't need that' said Lu-Tze kindly. 'It was a good challenge. A decent “Ai!” and a very passable “Hai-eee!”, I thought. Good martial gibberish all round, such as you don't often hear these days. And we would not want his trousers falling down at a time like this, would we?' He sniffed and added, 'Especially at a time like this.' He patted the shrinking man on the shoulder. 'Just you recall the rule your teacher here taught you on day one, eh? And... why don't you go and clean yourself up? I mean, some of us have to tidy up in here.' Then he turned and nodded to the dojo master. 'While I am here, master, I should like to show young Lobsang the Device of Erratic Balls.' The dojo master bowed deeply. 'It is yours, Lu-Tze the Sweeper.' As Lobsang followed the ambling Lu-Tze he heard the dojo master, who like all teachers never missed an opportunity to drive home a lesson, say: 'Dojo! What is Rule One?' Even the cowering challenger mumbled along to the chorus: 'Do not act incautiously when confronting little bald wrinkly smiling men!'

'Good rule, Rule One,' said Lu-Tze, leading his new acolyte into the next room. 'I have met many people who could have heeded it to good advantage.' He stopped, without looking at Lobsang Ludd, and held out his hand. 'And now, if you please, you will return the little shovel you stole from me when first we met.'

'But I came nowhere near you, master!' Lu-Tze's smile did not flicker. 'Oh. Yes. That is true. My apologies. The ramblings of an old man. Is it not written, “I'd forget my own head if it wasn't nailed on”? Let us proceed.' The floor in here was wood, but the walls were high and padded. There were reddish-brown stains here and there. 'Er, we have one of these in the novices' dojo, Sweeper,' said Lobsang. 'But the balls in that are made of soft leather, yes?' said the old man, approaching a tall wooden cube. A row of holes ran halfway up the side that faced down the length of the room. 'And they travel quite slowly, I recall.'

'Er, yes,' said Lobsang, watching him pull on a very large lever. Down below there was the sound of metal on metal, and then of urgent gushing water. Air began to wheeze from joints in the box. 'These are wooden,' said Lu-Tze calmly. 'Catch one.' Something touched Lobsang's ear and behind him the padding shook as a ball buried itself deeply and then dropped to the floor. 'Perhaps a shade slower ...' said Lu-Tze, turning a knob. After fifteen random balls, Lobsang caught one in his stomach. Lu-Tze sighed and pushed the big lever back. 'Well done,' he said. 'Sweeper, I'm not used to-' said the boy, picking himself up. 'Oh, I knew you wouldn't catch one,' said Lu-Tze. 'Even our boisterous friend out there in the dojo wouldn't catch one at that speed.'

'But you said you had slowed it down!'

'Only so that it wouldn't kill you. Just a test, see. Everything's a test. Let's go, lad. Can't keep the abbot waiting.' Trailing cigarette smoke, Lu-Tze ambled away. Lobsang followed, getting more and more nervous. This was Lu-Tze, the dojo had proved that. And he knew it, anyway. He'd looked at the little round face as it gazed amicably at the angry fighter and known it. But... just a sweeper? No insignia? No status? Well, obviously status, because the dojo master couldn't have bowed lower for the abbot, but...

And now he was following the man along passages where even a monk was not allowed to go, on pain of death. Sooner or later, there was surely going to be trouble. 'Sweeper, I really ought to be back at my duties in the kitchens-' he began. 'Oh, yes. Kitchen duties,' said Lu-Tze. 'To teach you the virtues of obedience and hard work, right?'

'Yes, Sweeper.'

'Are they working?'

'Oh, yes.'

'Really?'

'Well, no.'

'They're not all they're cracked up to be, I have to tell you,' said Lu-Tze. 'Whereas, my lad, what we have here' - he stepped through an archway - 'is an education!' It was the biggest room Lobsang had ever seen. Shafts of light speared down from glazed holes in the roof. And below, more than a hundred yards across, and tended by senior monks who walked above it on delicate wire walkways, was... Lobsang had heard about the Mandala. It was as if someone had taken tons of coloured sands and thrown them across the floor in a great swirl of coloured chaos. But there was order fighting for survival in the chaos, rising and falling and spreading. Millions of randomly tumbling sand grains would nevertheless make a piece of pattern, which would replicate and spread across the circle, rebounding or merging with other patterns and eventually dissolving into the general disorder. It happened again and again, turning the Mandala into a silent raging war of colour. Lu-Tze stepped out onto a frail-looking wood and rope bridge. 'Well?' he said. 'What d'you think?' Lobsang took a deep breath. He felt that if he fell off the bridge he'd drop into the surging colours and never, ever hit the floor. He blinked and rubbed his forehead. 'It's... evil,' he said. 'Really?' said Lu-Tze. 'Not many people say that the first time. They use words like “wonderful”.'

'It's going wrong!'

'What?' Lobsang clutched the rope railing. 'The patterns-' he began.

'History repeating,' said Lu-Tze. 'They're always there.'

'No, they're-' Lobsang tried to take it all in. There were patterns under the patterns, disguised as part of the chaos. 'I mean... the other patterns...' He slumped forward. The air was cold, the world was spinning, and the ground rushed up to enfold him. And stopped, a few inches away. The air around him sizzled, as though it was being gently fried. 'Newgate Ludd?'

'Lu-Tze?' he said. The Mandala is...' But where were the colours? Why was the air wet and smelling of the city? And then the ghost memories faded away. As they disappeared, they said: How can we be memories, when we have yet to happen? Surely what you remember is climbing all the way up onto the roof of the Bakers' Guild and finding that someone had loosened all the capping stones, because that just happened? And a last dying memory said, Hey, that was months ago ... 'No, we're not Lu-Tze, mysterious falling kid,' said the voice that had addressed him. 'Can you turn round?' Newgate managed, with great difficulty, to move his head. It felt as though he was stuck in tar. A heavy young man in a grubby yellow robe was sitting on an upturned box a few feet away. He looked a bit like a monk, except for his hair, because his hair looked a bit like an entirely separate organism. To say that it was black and bound up in a ponytail is to miss the opportunity of using the term 'elephantine'. It was hair with personality. 'Mostly my name's Soto,' said the man underneath. 'Marco Soto. I won't bother memorizing yours until we know if you're going to live or not, eh? So tell me, have you ever considered the rewards of the spiritual life?'

'Right now? Certainly!' said... yes, Newgate, he thought, that's my name, yes? So why do I remember Lobsang? 'Er, I was thinking about the possibility of taking up a new line of work!'

'Good career move,' said Soto. 'Is this some kind of magic?' Newgate tried to move but hung, turning gently, in the air just above the waiting ground. 'Not exactly. You seem to have shaped time.'