It reached the pointy ears of the dwarfs.
'Can we?'
'Damned if I know. I can't.'
'Yeah, but if you could, you wouldn't say. I wouldn't say, if I could.'
'Can you?'
'No!'
'Ah-ha!'
It came to the ears of the Night Watch of the city guard, as they did gate duty at ten o'clock on an icy night. Gate duty in Ankh-Morpork was not taxing. It consisted mainly of waving through anything that wanted to go through, although traffic was minimal in the dark and freezing fog.
They hunched in the shelter of the gate arch, sharing one damp cigarette.
'You can't turn something into something else,' said Corporal Nobbs. The Alchemists have been trying it for years.'
They can gen'rally turn a house into a hole in the ground,' said Sergeant Colon.
That's what I'm talking about,' said Corporal Nobbs. 'Can't be done. It's all to do with... elements. An alchemist told me. Everything's made up of elements, right? Earth, Water, Air, Fire and... sunnink. Well-known fact. Everything's got 'em all mixed up just right.'
He stamped his feet in an effort to get some warmth into them.
'If it was possible to turn lead into gold, everyone'd be doing it,' he said.
'Wizards could do it,' said Sergeant Colon.
'Oh, well, magic,' said Nobby dismissively.
A large cart rumbled out of the yellow clouds and entered the arch, splashing Colon as it wobbled through one of the puddles that were such a feature of Ankh-Morpork's highways.
'Bloody dwarfs,' he said, as it continued on into the city. But he didn't say it too loudly.
There were a lot of them pushing that cart,' said Corporal Nobbs reflectively. It lurched slowly round a corner and was lost to view.
'Prob'ly all that gold,' said Colon.
'Hah. Yeah. That'd be it, then.'
And the rumour came to the ears of William de Worde, and in a sense it stopped there, because he dutifully wrote it down.
It was his job. Lady Margolotta of Uberwald sent him five dollars a month to do it. The Dowager Duchess of Quirm also sent him five dollars. So did King Verence of Lancre, and a few other Ramtop notables. So did the Seriph of Al Khali, although in his case the payment was half a cartload of figs, twice a year.
All in all, he considered, he was on to a good thing. All he had to do was write one letter very carefully, trace it backwards on to a piece of boxwood provided for him by Mr Cripslock the engraver in the Street of Cunning Artificers, and then pay Mr Cripslock twenty dollars to carefully remove the wood that wasn't letters and make five impressions on sheets of paper.
Of course, it had to be done thoughtfully, with spaces left after To my Noble Client the', and so on, which he had to fill in later, but even deducting expenses it still left him the best part of thirty dollars for little more than one day's work a month.
A young man without too many responsibilities could live modestly in Ankh-Morpork on thirty or forty dollars a month; he always sold the figs, because although it was possible to live on figs you soon wished you didn't.
And there were always additional sums to be picked up here and there. The world of letters was a closed boo-- mysterious papery object to many of Ankh-Morpork's citizens, but if they ever did need to commit things to paper quite a few of them walked up the creaky stairs past the sign 'William de Worde: Things Written Down'.
Dwarfs, for example. Dwarfs were always coming to seek work in the city, and the first thing they did was send a letter home saying how well they were doing. This was such a predictable occurrence, even if the dwarf in question was so far down on his luck that he'd been forced to eat his helmet, that William had Mr Cripslock produce several dozen stock letters which needed only a few spaces filled in to be perfectly acceptable.
Fond dwarf parents all over the mountains treasured letters which looked something like this:
Dear [Mume & Dad],
Well, I arrived here all right and I am staying, at [109 Cockbill Street The Shades Ankh-Morpk]. Everythyng is fine. I have got a goode job working for [Mr C.M.O.T. Dibbler, Merchant Venturer] and will be makinge lots of money really soon now. I am rememberinge alle your gode advyce and am not drinkynge, in bars or mixsing with Trolls. Well thas about itte mu,'t goe now, looking forwade to seing you and [Emelia] agane, your loving son,
[Tomas Brokenbrow]
... who was usually swaying while he dictated it. It was twenty pence easily made, and as an additional service William carefully tailored the spelling to the client and allowed them to choose their own punctuation.
On this particular evening, with the sleet gurgling in the downspouts outside his lodgings, William sat in the tiny office over the Guild of Conjurors and wrote carefully, half listening to the hopeless but painstaking catechism of the trainee conjurors at their evening class in the room below.
'... pay attention. Are you ready? Right. Egg. Glass...'
'Egg. Glass,' the class droned listlessly.
'... Glass. Egg...'
'Glass. Egg ...'
'... Magic word...'
'Magic word... '
'Fazammm. Just like that. Ahahahahaha...'
'Faz-ammm. Just like that. Aha-ha-ha-ha-ha...'
William pulled another sheet of paper towards him, sharpened a fresh quill, stared at the wall for a moment and then wrote as follows:
And finally, on the lighter Side, it is being said that the Dwarfs can Turn Lead into Gold, though no one knows whence the rumour comes, and Dwarfs going about their lawful occa,'ions in the City are hailed with cries such as, e.g., 'Hollah, short stuff, let's see you make some Gold then!' although only Newcomers do this because all here know what happens if you call a Dwarf 'short stuff, viz., you are Dead.
Yr. obdt. servant, William de Worde
He always liked to finish his letters on a happy note.
He fetched a sheet of boxwood, lit another candle and laid the letter face down on the wood. A quick rub with the back of a spoon transferred the ink, and thirty dollars and enough figs to make you really ill were as good as in the bank.
He'd drop it into Mr Cripslock tonight, pick up the copies after a leisurely lunch tomorrow, and with any luck should have them all away by the middle of the week.
William put on his coat, wrapped the wood block carefully in some waxed paper and stepped out into the freezing night.
The world is made up of four elements: Earth, Air, Fire and Water. This is a fact well known even to Corporal Nobbs. It's also wrong. There's a fifth element, and generally it's called Surprise.
For example, the dwarfs found out how to turn lead into gold by doing it the hard way. The difference between that and the easy way is that the hard way works.
The dwarfs dwarfhandled their overloaded, creaking cart along the street, peering ahead in fog. Ice formed on the cart and hung from their beards.
All it needed was one frozen puddle.
Good old Dame Fortune. You can depend on her.
The fog closed in, making every light a dim glow and muffling all sounds. It was clear to Sergeant Colon and Corporal Nobbs that no barbarian horde would be including the invasion of Ankh-Morpork in their travel plans for this evening. The watchmen didn't blame them.
They closed the gates. This was not the ominous activity that it might appear, since the keys had been lost long ago and latecomers usually threw gravel at the windows of the houses built on top of the wall until they found a friend to lift the bar. It was assumed that foreign invaders wouldn't know which windows to throw gravel at.
Then the two watchmen trailed through the slush and muck to the Water Gate, by which the river Ankh had the good fortune to enter the city. The water was invisible in the dark, but the occasional ghostly shape of an ice floe drifted past below the parapet.
'Hang on,' said Nobby, as they laid hands on the windlass of the portcullis. 'There's someone down there.'
'In the river?' said Colon.
He listened. There was the creak of an oar, far below.
Sergeant Colon cupped his hands around his mouth and issued the traditional policeman's cry of challenge.
'Oi! You!'
For a moment there was no sound but the wind and the gurgling of the water. Then a voice said: 'Yes?'
'Are you invading the city or what?'
There was another pause. Then:
'What?'
'What what?' said Colon, raising the stakes.
'What were the other options?'
'Don't mess me about... Are you, down there in the boat, invading this city?'
'No.'
'Fair enough,' said Colon, who on a night like this would happily take someone's word for it. 'Get a move on, then, 'cos we're going to drop the gate.'
After a while the splash of the oars resumed and disappeared downriver.
'You reckon that was enough, just askin' 'em?' said Nobby.
'Well, they ought to know,' said Colon.
'Yeah, but--'
'It was a tiny little rowin' boat, Nobby. Of course, if you want to go all the way down to them nice icy steps on the jetty--'
'No, sarge.'
'Then let's get back to the Watch House, all right?'
William turned up his collar as he hurried towards Cripslock the engraver. The usually busy streets were deserted. Only those people with the most pressing business were out of doors. It was turning out to be a very nasty winter indeed, a gazpacho of freezing fog, snow and Ankh-Morpork's ever-present, ever-rolling smog.
His eye was caught by a little pool of light by the Watchmakers' Guild. A small hunched figure was outlined in the glow.
He wandered over.
A hopeless sort of voice said, 'Hot sausages? Inna bun?'
'Mr Dibbler?' said William.
Cut-Me-Own-Throat Dibbler, Ankh-Morpork's most enterprisingly unsuccessful businessman, peered at William over the top of his portable sausage-cooking tray. Snowflakes hissed in the congealing fat.
William sighed. 'You're out late, Mr Dibbler,' he said politely.
'Ah, Mr Word. Times is hard in the hot sausage trade,' said Dibbler.
'Can't make both ends meat, eh?' said William. He couldn't have stopped himself for a hundred dollars and a shipload of figs.
'Definitely in a period of slump in the comestibles market,' said Dibbler, too sunk in gloom to notice. 'Don't seem to find anyone ready to buy a sausage in a bun these days.'
William looked down at the tray. If Cut-Me-Own-Throat Dibbler was selling hot sausages, it was a sure sign that one of his more ambitious enterprises had gone wahoonie-shaped yet again. Selling hot sausages from a tray was by way of being the ground state of Dibbler's existence, from which he constantly sought to extricate himself and back to which he constantly returned when his latest venture went all runny. Which was a shame, because Dibbler was an extremely good hot sausage salesman. He had to be, given the nature of his sausages.
'I should have got a proper education like you,' said Dibbler despondently. 'A nice job indoors with no heavy lifting. I could have found my nitch, if'n I'd have got a good education.'
'Nitch?'
'One of the wizards told me about 'em,' said Dibbler. 'Everything's got a nitch. You know. Like: where they ought to be. What they was cut out for?'
William nodded. He was good with words. 'Niche?' he said.
'One of them things, yes.' Dibbler sighed. 'I missed out on the semaphore. Just didn't see it coming. Next thing you know, everyone's got a clacks company. Big money. Too rich for my blood. I could've done all right with the Fung Shooey, though. Sheer bloody bad luck there.'
'I've certainly felt better with my chair in a different position,' said William. That advice had cost him two dollars, along with an injunction to keep the lid down on the privy so that the Dragon of Unhappiness wouldn't fly up his bottom.
'You were my first customer and I thank you,' said Dibbler. 'I was all set up, I'd got the Dibbler wind-chimes and the Dibbler mirrors, it was gravy all the way - I mean, everything was positioned for maximum harmony, and then... smack. Bad karma plops on me once more.' ,
'It was a week before Mr Passmore was able to walk again, though,' said William. The case of Dibbler's second customer had been very useful for his news letter, which rather made up for the two dollars.
'I wasn't to know there really is a Dragon of Unhappiness,' said Dibbler.
'I don't think there was until you convinced him that one exists,' said William.
Dibbler brightened a little. 'Ah, well, say what you like, I've always been good at selling ideas. Can I convince you of the idea that a sausage in a bun is what you desire at this time?'
'Actually, I've really got to get this along to--' William began, and then said, 'Did you just hear someone shout?'
'I've got some cold pork pies, too, somewhere,' said Dibbler, ferreting in his tray. 'I can give you a convincingly bargain price on--'
'I'm sure I heard something,' said William.
Dibbler cocked an ear. 'Sort of like a rumbling?' he said.
'Yes.'
They stared into the slowly rolling clouds that filled Broad Way.
Which became, quite suddenly, a huge tarpaulin-covered cart, moving unstoppably and very fast...
And the last thing William remembered, before something flew out of the night and smacked him between the eyes, was someone shouting, 'Stop the press!'
The rumour, having been pinned to the page by William's pen like a butterfly to a cork, didn't come to the ears of some people, because they had other, darker things on their mind.
Their rowboat slid through the hissing waters of the river Ankh, which closed behind it slowly.
Two men were bent over the oars. The third sat in the pointy end. Occasionally he spoke.
He said things like 'My nose itches.'
'You'll just have to wait till we get there,' said one of the rowers.
'You could let me out again. It really itches.'
'We let you out when we stopped for supper.'
'It didn't itch then.'
The other rower said, 'Shall I hit him up alongside the --ing head with the --ing oar again, Mr Pin?'
'Good idea, Mr Tulip.'
There was a dull thump in the darkness.
'Ow.'
'Now no more fuss, friend, otherwise Mr Tulip will Jose his temper.'
Too --ing right.' Then there was a sound like an industrial pump.
'Hey, go easy on that stuff, why don't you?'
'Ain't --ing killed me yet, Mr Pin.'
The boat oozed to a halt alongside a tiny, little-used landing stage. The tall figure who had so recently been the focus of Mr Pin's attention was bundled ashore and hustled down an alley.
A moment later there was the sound of a carriage rolling away into the night.
It would seem quite impossible, on such a mucky night, that there could have been anyone to witness this scene.
But there was. The universe requires everything to be observed, lest it cease to exist.
A figure shuffled out from the shadows of the alley, close by. There was a smaller shape wobbling uncertainly by its side.
Both of them watched the departing coach as it disappeared into the snow.
The smaller of the two figures said, 'Well, well, well. There's a fing. Man all bundled up and hooded. An interesting fing, eh?'
The taller figure nodded. It wore a huge old greatcoat several sizes too big, and a felt hat that had been reshaped by time and weather into a soft cone that overhung the wearer's head.
'Scraplit,' it said. 'Thatch and trouser, a blewit the grawney man. I told 'im. I told 'im. Millennium hand and shrimp. Bugrit.'
After a pause it reached into its pocket and produced a sausage, which it broke into two pieces. One bit disappeared under the hat, and the other was tossed to the smaller figure, who was doing most of the talking or, at least, most of the coherent talking.
'Looks like a dirty deed to me,' said the smaller figure, which had four legs.
The sausage was consumed in silence. Then the pair set off into the night again.
In the same way that a pigeon can't walk without bobbing its head, the taller figure appeared unable to move without a sort of low-key, random mumbling:
'I told 'em, I told 'em. Millennium hand and shrimp. I said, I said, I said. Oh, no. But they only run out, I told 'em. Sod 'em. Doorsteps. I said, I said, I said. Teeth. Wassa name of age, I said I told 'em, not my fault, matterofact, matterofact, stands to reason...'
The rumour did come to his ears later on, but by then he was part of it.
As for Mr Pin and Mr Tulip, all that need be known about them at this point is that they are the kind of people who call you 'friend'. People like that aren't friendly.
William opened his eyes. I've gone blind, he thought.
Then he moved the blanket.
And then the pain hit him.
It was a sharp and insistent sort of pain, centred right over the eyes. He reached up gingerly. There seemed to be some bruising and what felt like a dent in the flesh, if not the bone.
He sat up. He was in a sloping-ceilinged room. A bit of grubby snow crusted the bottom of a small window. Apart from the bed, which was just a mattress and blanket, the room was unfurnished.
A thump shook the building. Dust drifted down from the ceiling) He got up, clutching at his forehead, and staggered to the door. It opened into a much larger room or, more accurately, a workshop.
Another thump rattled his teeth.
William tried to focus.
The room was full of dwarfs, toiling over a couple of long benches. But at the far end several of them were clustered around something like a complex piece of weaving machinery.
It went thump again.
William rubbed his head. 'What's happening?' he said.
The nearest dwarf looked up at him and nudged a colleague urgently. The nudge passed itself along the rows, and the room was suddenly filled wall to wall with a cautious silence. A dozen solemn dwarf faces looked hard at William.
No one can look harder than a dwarf. Perhaps it's because there is only quite a small amount of face between the statutory round iron helmet and the beard. Dwarf expressions are more concentrated.
'Urn,' he said. 'Hello?'
One of the dwarfs in front of the big machine was the first to unfreeze.
'Back to work, lads,' he said, and came and looked William sternly in the groin.
'You all right, your lordship?' he said.
William winced. 'Um... what happened?' he said. 'I, uh, remember seeing a cart, and then something hit...'
'It ran away from us,' said the dwarf. 'Load slipped, too. Sorry about that.'
'What happened to Mr Dibbler?'
The dwarf put his head on one side. 'The skinny man with the sausages?' he said.
'That's right. Was he hurt?'
'I don't think so,' said the dwarf carefully. 'He sold young Thunderaxe a sausage in a bun, I do know that.'
William thought about this. Ankh-Morpork had many traps for the unwary newcomer.
'Well, then, is Mr Thunderaxe all right?' he said.
'Probably. He shouted under the door just now that he was feeling a lot better but would stay where he was for the time being,' said the dwarf. He reached under a bench and solemnly handed William a rectangle wrapped in grubby paper.
'Yours, I think,'
William unwrapped his wooden block. It was split right across where a wheel of the cart had run over it, and the writing had been smudged. He sighed.
' 'scuse me,' said the dwarf, 'but what was it meant to be?'
'It's a block prepared for a woodcut,' said William. He wondered how he could possibly explain the idea to a dwarf from outside the city. 'You know? Engraving? A... a sort of very nearly magical way of getting lots of copies of writing? I'm afraid I shall have to go and make another one now,'
The dwarf gave him an odd look, and then took the block from him and turned it over and over in his hands.
'You see,' said William, 'the engraver cuts away bits of--'
'Have you still got the original?' said the dwarf.
'Pardon?'
'The original,' said the dwarf patiently.
'Oh, yes,' William reached inside his jacket and produced it.
'Can I borrow it for a moment?'
'Well, all right, but I shall need it again to--'
The dwarf scanned the letter a while, and then turned and hit the nearest dwarf a resounding boing on the helmet.
'Ten point across three,' he said, handing him the paper. The struck dwarf nodded, and then its right hand moved quickly across the rack of little boxes, selecting things.
'I ought to be getting back so I can--' William began.
'This won't take long,' said the head dwarf. 'Just you step along this way, will you? This might be of interest to a man of letters such as yourself,'
William followed him along the avenue of busy dwarfs to the machine, which had been thumping away steadily.
'Oh. It's an engraving press,' said William vaguely.
'This one's a bit different,' said the dwarf. 'We've... modified it,' He took a large sheet of paper off a pile by the press and gave it to William, who read:
GUNILLA GOODMOUNTAIN & CO.
Reƒpectfully Solicit
Work for their New
WORD SMITHY
A method of taking multiple impresfions
the like of which
Hath not hiterto been Seen.
Reaƒbnable rates.
At the Sign of The Bucket, Gleam Street,
off Treacle Mine Road, Ankh-Morpork.
'What do you think?' said the dwarf shyly.
'Are you Gunilla Goodmountain?'
'Yes. What do you think?'
'We-ell... you've got the letters nice and regular, I must say,' said William. 'But I can't see what's so new about it. And you've spelled "hitherto" wrong. There should be another h after the first t. You'll have to cut it all out again unless you want people to laugh at you,'
'Really?' said Goodmountain. He nudged one of his colleagues.
'Just give me a ninety-six-point lower-case h, will you, Caslong? Thank you,'
Goodmountain bent over the press, picked up a spanner and busied himself somewhere in the mechanical gloom.
'You must have a really steady hand to get the letters so neat,' said William. He felt a bit sorry that he'd pointed out the mistake. Probably no one would have noticed in any case. Ankh-Morpork people considered that spelling was a sort of optional extra. They believed in it in the same way they believed in punctuation; it didn't matter where you put it so long as it was there.
The dwarf finished whatever arcane activity he had been engaged in, dabbed with an inked pad at something inside the press, and got down.
'I'm sure it won't' - thump - 'matter about the spelling,' said William.
Goodmountain opened the press again and wordlessly handed William a damp sheet of paper.
William read it.
The extra h was in place.
'How--?' he began.
'This is a very nearly magical way of getting lots of copies quickly,' said Goodmountain. Another dwarf appeared at his elbow, holding a big metal rectangle. It was full of little metal letters, back to front. Goodmountain took it and gave William a big grin.
'Want to make any changes before we go to press?' he said. 'Just say the word. A couple of dozen prints be enough?'
'Oh dear,' said William. This is printing, isn't it... ?'
The Bucket was a tavern, of sorts. There was no passing trade. The street was if not a dead end then seriously wounded by the area's change in fortunes. Few businesses fronted on to it. It consisted mainly of the back ends of yards and warehouses. No one even remembered why it was called Gleam Street. There was nothing very sparkling about it.
Besides, calling a tavern the Bucket was not a decision destined to feature in Great Marketing Decisions of History. Its owner was Mr Cheese, who was thin, dry and only smiled when he heard news of some serious murder. Traditionally he had sold short measure but, to make up for it, had short-changed as well. However, the pub had been taken over by the City Watch as the unofficial policemen's pub, because policemen like to drink in places where no one else goes and they don't have to be reminded that they are policemen.
This had been a benefit in some ways. Not even licensed thieves tried to rob the Bucket now. Policemen didn't like their drinking disturbed. On the other hand, Mr Cheese had never found a bigger bunch of petty criminals than those wearing the Watch uniform. He saw more dud dollars and strange pieces of foreign currency cross his bar in the first month than he'd found in ten years in the business. It made you depressed, it really did. But some of the murder descriptions were quite funny.
He made part of his living by renting out the rat's nest of old sheds and cellars that backed on to the pub. They tended to be occupied very temporarily by the kind of enthusiastic manufacturer who believed that what the world really, really needed today was an inflatable dartboard.
But there was a crowd outside the Bucket now, reading one of the' slightly misprinted posters that Goodmountain had nailed up on the door. Goodmountain followed William out and nailed up the corrected version.
'Sorry about your head,' he said. 'Looks like we made a bit of an impression on you. Have this one on the house.'
William skulked home, keeping in the shadows in case he met Mr Cripslock. But he folded his printed sheets into their envelopes and took them down to the Hubward Gate and gave them to the messengers, reflecting as he did so that he was doing this several days before he had expected to.
The messengers gave him some very odd looks.
He went back to his lodgings and had a look at himself in the mirror over the washbasin. A large R, printed in bruise colours, Occupied a lot of his forehead.
He stuck a bandage over it.
And he still had eighteen more copies. As an afterthought, and feeling rather daring, he looked through his notes for the addresses of eighteen prominent citizens who could probably afford it, wrote a short covering letter to each one offering this service for... he thought for a while and then carefully wrote '$5'... and folded the free sheets into eighteen envelopes. Of course, he could always have asked Mr Cripslock to do more copies as well, but it had never seemed right. After the old boy had spent all day chipping out the words, asking him to sully his craftsmanship by making dozens of duplicates seemed disrespectful. But you didn't have to respect lumps of metal and machines. Machines weren't alive.
That, really, was where the trouble was going to start. And there was going to be trouble. The dwarfs had seemed quite unconcerned when he'd told them how much of it there was going to be.
The coach arrived at a large house in the city. A door was opened. A door was shut. Another door was knocked on. It was opened. It shut. The carriage pulled away.
One ground-floor room was heavily curtained, and only the barest gleam of light filtered out. Only the faintest of noises filtered out, too, but any listener would have heard a murmur of conversation die down. Then a chair was knocked over and several people shouted, all at once.
'That is him!'
'It's a trick... isn't it?'
'I'll be damned!'
'If it is him, so are we all!'
The hubbub died away. And then, very calmly, someone began to talk.
'Good. Good. Take him away, gentlemen. Make him comfortable in the cellar.'
There were footsteps. A door opened and closed.
A more querulous voice said, 'We could simply replace--'
'No, we could not. I understand that our guest is, fortunately, a man of rather low intelligence.' There was this about the first speaker's voice. It spoke as if disagreeing was not simply unthinkable but impossible. It was used to being in the company of listeners.
'But he looks the spit and image--'
'Yes. Astonishing, isn't it? Let us not overcomplicate matters, though. We are a bodyguard of lies, gentlemen. We are all that stands between the city and oblivion, so let us make this one chance work. Vetinari may be quite willing to see humans become a minority in their greatest city, but frankly his death by assassination would be... unfortunate. It would cause turmoil, and turmoil is hard to steer. And we all know that there are people who take too much of an interest. No. There is a third way. A gentle slide from one condition to another.'
'And what will happen to our new friend?'
'Oh, our employees are known to be men of resource, gentlemen. I'm sure they know how to deal with a man whose face no longer fits, eh?'
There was laughter.
Things were a little fraught in Unseen University. The wizards were scuttling from building to building, glancing at the sky.
The problem, of course, was the frogs. Not rains of frogs, which were uncommon now in Ankh-Morpork, but specifically foreign treefrogs from the humid jungles of Klatch. They were small, brightly coloured, happy little creatures who secreted some of the nastiest toxins in the world, which is why the job of looking after the large vivarium where they happily passed their days was given to first-year students, on the basis that if they got things wrong there wouldn't be too much education wasted.
Very occasionally a frog was removed from the vivarium and put into a rather smaller jar where it briefly became a very happy frog indeed, and then went to sleep and woke up in that great big jungle in the sky.
And thus the University got the active ingredient which it made up into pills and fed to the Bursar, to keep him sane. At least, apparently sane, because nothing was that simple at good old UU. In fact he was incurably insane and hallucinated more or less continuously, but by a remarkable stroke of lateral thinking his fellow wizards had reasoned that, in that case, the whole business could be sorted out if only they could find a formula that caused him to hallucinate that he was completely sane*
[* This is a very common hallucination, shared by most people.]
This had worked well. There had been a few false starts. For several hours, at one point, he had hallucinated that he was a bookcase. But now he was permanently hallucinating that he was a bursar, and that almost made up for the small side-effect that also led him to hallucinate that he could fly.
Of course, many people in the universe have also had the misplaced belief that they can safely ignore gravity, mostly after taking some local equivalent of dried frog pills, and this has led to much extra work for elementary physics and caused brief traffic jams in the street below. When a wizard hallucinates that he can fly, things are different.
'Bursaar! You come down here right this minute!' Arch-chancellor Mustrum Ridcully barked through his megaphone. 'You know what I said about goin' higher than the walls!'