Susan stepped out of the light and her wrist moved. A sparkling blue line flashed in the air, for a moment outlining an edge too thin to be seen. The oh god backed away. 'What's that?'

'Oh, it cuts tiny bits of the air in half. It can cut the soul away from the body, so stand back, please.'

'Oh, I will, I will.' Susan fished the black scabbard out of the umbrella stand. Umbrella stand! It never rained here, but Death had an umbrella stand. Practically no one else Susan knew had an umbrella stand. In any list of useful furniture, the one found at the bottom would be the umbrella stand. Death lived in a black world, where nothing was alive and everything was dark and his great library only had dust and cobwebs because he'd created them for effect and there was never any sun in the sky and the air never moved and he had an umbrella stand. And a pair of silverbacked hairbrushes by his bed. He wanted to be something more than just a bony apparition. He tried to create these flashes of personality but somehow they betrayed themselves, they tried too hard, like an adolescent boy going out wearing an aftershave called 'Rampant'. Grandfather always got things wrong. He saw life from outside and never quite understood. 'That looks dangerous,' said the oh god. Susan sheathed the sword. 'I hope so,' she said. 'Er ... where are we going? Exactly?'

'Somewhere under an overhead sky,' said Susan. 'And ... I've seen it before. Recently. I know the place.' They walked out to the stable yard. Binky was waiting. 'I said you don't have to come,' said Susan, grasping the saddle. 'I mean, you're a ... an innocent bystander.'

'But I'm a god of hangovers who's been cured of hangovers,' said the oh god. 'I haven't really got any function at all.' He looked so forlorn when he said this that she relented. 'All right. Come on, then.' She pulled him up behind her. 'Just hang on,' she said. And then she said, `Hang on somewhere differently, I mean.'

'I'm sorry, was that a problem?' said the oh god, shifting his grip. 'It might take too long to explain and you probably don't know all the words. Around the waist, please.' Susan took out Violet's hourglass and held it up. There was a lot of sand left to run, but she couldn't be certain that was a good sign. All she could be certain of was that the horse of Death could go anywhere. The sound of Hex's quill as it scrabbled across the paper was like a frantic spider trapped in a matchbox. Despite his dislike of what was going on, there was a part of Ponder Stibbons that was very, very impressed. In the past, when Hex had been recalcitrant about its calculations, when it had got into a mechanical sulk and had started writing things like'+++ Out of Cheese Error +++'and'+++ Redo From Start +++' Ponder had tried to sort things out calmly and logically. It had never, ever occurred to him to contemplate hitting Hex with a mallet. But this was, in fact, what Ridcully was threatening to do.

What was impressive, and also more than a little worrying, was that Hex seemed to understand the concept. 'Right,' said Ridcully, putting the mallet aside. 'Let's have no more of this “Insufficient dates” business, shallwe? There's boxes of the damn things back in the Great Hall. You can have the lot as far as Im concerned---'

'It's data, not dates,' said Ponder helpfully. 'What? You mean like ... more than dates? Extra sticky?'

'No, no, data is Hex's word for ... well, facts,' said Ponder. 'Ridiculous way to behave,' said Ridcully brusquely. 'If he's stumped for an answer, why can't he write “You've got me there” or “Damned if I know,” or “That's a bit of a puzzler and no mistake”? All this “Insufficient data” business is just pure contrariness, to my mind. It's just swank-' He turned back to Hex. 'Right, you. Hazard a guess.' The quill started to write '+++ Insuff ' and then stopped. After quivering for a moment it went down a line and started again. +++ This Is Just Calculating Aloud, You Understand +++ 'Fair enough,' said Ridcully. .+++ The Amount Of Belief In The World Must Be Subject To An Upper Limit +++ 'What an odd question,' said the Dean. 'Sounds sensible,' said Ridcully. 'I suppose people just ... believe in stuff. Obviously there's a limit to what you can believe in. I've always said so. So what?' .+++ Creatures Have Appeared That Were Once Believed In +++ 'Yes. Yes, you could put it like that.' +++ They Disappeared Because They Were Not Believed In +++ 'Seems reasonable,' said Ridcully. +++ People Were Believing In Something Else Query? +++ Ridcully looked at the other wizards. They shrugged. 'Could be,' he said guardedly. 'People can only believe in so many things.' ... It Follows That If A Major Focus Of Belief Is Removed, There Will Be Spare Belief ... Ridcully stared at the words. 'You mean ... sloshing around?' The big wheel with the ram skulls on it began to turn ponderously. The scurrying ants in the .glass tubes took on a new urgency. 'What's happening?' said Ridcully, in a loud whisper. 'I think Hex is looking up the word “sloshing”,' said Ponder. 'It may be in long-term storage.' A large hourglass came down on the spring. 'What's that for?' said Ridcully. 'Er ... it shows Hex is working things out.'

'Oh. And that buzzing noise? Seems to be coming from the other side of the wall.' Ponder coughed. 'That is the long-term storage, Archchancellor.'

'And how does that work?'

'Er ... well, if you think of memory as a series of little shelves or, or, or holes, Archchancellor, in which you can put things, well, we found a way of making a sort of memory which, er, interfaces neatly with the ants, in fact, but more importantly can expand its size depending on how much we give it to remember and, er, is possibly a bit slow but----'

'It's a very loud buzzing,' said the Dean. 'Is it going wrong. 'No, that shows it's working,' said Ponder. 'It's, er, beehives.' He coughed.

'Different types of pollen, different thicknesses of honey, placement of the eggs ... It's actually amazing how much information you can store on one honeycomb.' He looked at their faces. 'And it's very secure because anyone trying to tamper with it will get stung to death and Adrian believes that when we shut it down in the summer holidays we should get a nice lot of honey, too.' He coughed again. 'For our ... sand ... wiches,' he said. He felt himself getting smaller and hotter under their gazes. Hex came to his rescue. The hourglass bounced away and the quill pen was jerked in and out of its inkwell. +++ Yes. Sloshing Around. Accreting +++ 'That means forming around new centres, Archchancellor,' said Ponder helpfully. 'I know that,' said Ridcully. 'Blast. Remember when we had all that life force all over the place? A man couldn't call his trousers his own! So ... there's spare belief sloshing around, thank you, and these little devils are taking advantage of it? 'Coming back? Household gods?' +++ This Is Possible +++ 'All right, then, so what are people not believing in all of a sudden?' +++ Out Of Cheese Error +++ MELON MELON MELON +++ Redo From Start +++ 'Thank you. A simple “I don't know” would have been sufficient,' said Ridcully, sitting back. 'One of the major gods?' said the Chair of Indefinite Studies. 'Hah, we'd soon know about it if one of those vanished.'

'It's Hogswatch,' said the Dean. 'I suppose the Hogfather is around, is he?'

'You believe in him?' said Ridcully. 'Well, he's for kids, isn't he?' said the Dean. 'But I'm sure they all believe in him. I certainly did. It wouldn't be Hogswatch when I was a kid without a pillowcase hanging by the fire--.-'

'A pillowcase?' said the Senior Wrangler, sharply. 'Well, you can't get much in a stocking,' said the Dean. 'Yes, but a whole pillowcase?' the Senior Wrangler insisted. 'Yes. What of it?'

'Is it just me, or is that a rather greedy and selfish way to behave? In my family we just hung up very small socks,' said the Senior Wrangler. 'A sugar pig, a toy soldier, a couple of oranges and that was it. Hah, turns out people with whole pillowcases were cornering the market, eh?'

'Shut up and stop squabbling, both of you,' said Ridcully. 'There must be a simple way to check up. How can you tell if the Hogfather exists?'

'Someone's drunk the sherry, there's sooty footprints on the carpet, sleigh tracks on the roof and your pillowcase is full of presents,' said the Dean. 'Hah, pillowcase,' said the Senior Wrangler darkly. 'Hah. I expect your family were the stuck-up sort that didn't even open their presents until after Hogswatch dinner, eh? One of them with a big snooty Hogswatch tree in the hall?'

'What if---' Ridcully began, but he was too late. 'Well?' said the Dean. 'Of course we waited until after lunch---'

'You know, it really used to wind me right up, people with big snooty Hogswatch trees. And I just bet you had one of those swanky fancy nutcrackers like a big thumbscrew,' said the Senior Wrangler. 'Some people had to make do with the coal hammer out of the outhouse, of course. And had dinner in the middle of the day instead of lah-di-dah posh dinner in the evening.'

'I can't help it if my family had money,' said the Dean, and that might have defused things a bit had he not added, 'and standards.'

'And big pillowcases!' shouted the Senior Wrangler, bouncing up and down in rage. 'And I bet you bought your holly, eh?'

The Dean raised his eyebrows. 'Of course! We didn't go creeping around the country pinching it out of other people's hedges, like some people did,' he snapped. 'That's traditional! That's part of the fun!'

'Celebrating Hogswatch with stolen greenery?' Ridcully put his hand over his eyes. The word for this, he had heard, was 'cabin fever'. When people had been cooped up for too long in the dark days of the winter, they always tended to get on one another's nerves, although there was probably a school of thought that would hold that spending your time in a university with more than five thousand known rooms, a huge library, the best kitchens in the city, its own brewery, dairy, extensive wine cellar, laundry, barber shop, cloisters and skittle alley was testing the definition of 'cooped up' a little. Mind you, wizards could get on one another's nerves in opposite corners of a very large field. 'Just shut up, will you?' he said. 'It's Hogswatch! That's not the time for silly arguments, all right?'

'Oh, yes it is,' said the Chair of Indefinite Studies glumly. 'It's exactly the time for silly arguments. In our family we were lucky to get through dinner without a reprise of What A Shame Henry Didn't Go Into Business With Our Ron. Or Why Hasn't Anyone Taught Those Kids To Use A Knife? That was another favourite.'

'And the sulks,' said Ponder Stibbons. 'Oh, the sulks,' said the Chair of Indefinite Studies. 'Not a proper Hogswatch without everyone sitting staring at different walls.'

'The games were worse,' said Ponder. 'Worse than the kids hitting one another with their toys, do you think? Not a proper Hogswatch afternoon without wheels and bits of broken dolly everywhere and everyone whining. Assault and battery included.'

'We had a game called Hunt the Slipper,' said Ponder. 'Someone hid a slipper. And then we had to find it. And then we had a row.'

'It's not really bad,' said the Lecturer in Recent Runes. 'I mean, not proper Hogswatch bad, unless everyone's wearing a paper hat. There's always that bit, isn't there, when someone's horrible great-aunt puts on a paper hat and smirks at everyone because she's being so bohemian.'

'I'd forgotten about the paper hats,' said the Chair of Indefinite Studies. 'Oh, dear.'

'And then later on someone'll suggest a board game,' said Ponder. 'That's right. Where no one exactly remembers all the rules.'

'Which doesn't stop someone suggesting that you play for pennies.'

'And five minutes later there's two people not speaking to one another for the rest of their lives because of tuppence.'

'And some horrible little kid--'