Moist glanced at the array of masks, scary rubber hands and joke noses, and considered his needs satisfied. 'Only my change, Jack,' he said, and carefully laid one of his new creations on the counter. 'Just give me half a dollar.'

Proust stared at it as if it might explode or vent some mind-altering gas. 'What's this, sir?'

'A note for a dollar. A dollar bill. It's the latest thing.'

'Do I have to sign it or anything?'

'No. That's the interesting bit. It's a dollar. It can be anyone's.'

'I'd like it to be mine, thank you!'

'It is, now,' said Moist. 'But you can use it to buy things.'

'There's no gold in it,' said the shopkeeper, picking it up and holding it away from his body, just in case.

'Well, if I paid in pennies and shillings there would be no gold in them either, right? As it is, you're fifteen pence ahead, and that's a good place to be, agreed? And that note is worth a dollar. If you take it along to my bank, they'll give you a dollar for it.'

'But I've already got a dollar! Er, haven't I?' Proust added.

'Good man! So why not go out in the street and spend it right now? Come on, I want to see how it works.'

'Is this like the stamps, Mr Lipwig?' said Proust, clutching for something he could understand. 'People sometimes pay me in stamps, me doing a lot of mail-order—'

'Yes! Yes! Exactly! Think of it as a big stamp. Look, I'll tell you what, this is an introductory offer. Spend that dollar and I'll give you another bill for a dollar, so that you'll still have a dollar. So what are you risking?'

'Only if this is, like, one of the first dollar bills, right… well, my lad bought some of the first stamps you did, right, and now they're worth a mint, so if I hang on to it, it'll be worth money some day—'

'It's worth money now? Moist wailed. That was the trouble with slow people. Give him a fool any day. Slow people took some time to catch up, but when they did they rolled right over you.

'Yes, but, see,' and here the shopkeeper grinned what he probably thought was an artful grin that in fact made him look like Mr Fusspot halfway through a toffee, 'you're a sly one with them stamps, Mr Lipwig, bringin' out different ones all the time. My granny says if it's true a man's got enough iron in his blood to make a nail then you've got enough brass in your neck to make a doorknob, no offence meant, she speaks her mind does my granny—'

'I've made the mail run on time, haven't I?'

'Oh, yes, Gran says you may be a Slippery Jim but you get things done, no doubt about it—'

'Right! Let's spend a damn dollar, then, shall we?' Is it some kind of duplex magical power I have, he wondered, that lets old ladies see right through me but like what they see?

And thus Mr Proust decided to hazard his dollar in the shop next door, on an ounce of Jolly Sailor pipe tobacco, some mints and a copy of What Novelty?. And Mr 'Natty' Poleforth, once the exercise was explained, accepted the note and took it across the road to Mr Drayman the butcher, who cautiously accepted it, after having things set out fair and square for him, in payment for some sausages and also gave Moist a bone 'for your little doggie'. It was more than likely that Mr Fusspot had never seen a real bone before. He circled it carefully, waiting for it to squeak.

Tenth Egg Street was a street of small traders, who sold small things in small quantities for small sums on small profits. In a street like that, you had to be small-minded. It wasn't the place for big ideas. You had to look at the detail. These were men who saw far more farthings than dollars.

Some of the other shopkeepers were already pulling down the shutters and closing up for the day. Drawn by the Ankh-Morporkian's instinct for something interesting, the traders drifted over to see what was going on. They all knew one another. They all dealt with one another. And everyone knew Moist von Lipwig, the man in the gold suit. The notes were examined with much care and solemn discussion.

'It's just an IOU or marker, really.'

'All right, but supposing you needed the money?'

'But, correct me if I'm wrong, isn't the IOU the money?'

'All right then, who owes it to you?'

'Er… Jack here, because… No, hang on… it is the money, right?'

Moist grinned as the discussion wobbled back and forth. Whole new theories of money were growing here like mushrooms, in the dark and based on bullshit. But these were men who counted every half-farthing and slept at night with the cash box under their bed. They'd weigh out flour and raisins and hundreds-and-thousands with their eyes ferociously focused on the scale's pointer, because they were men who lived in the margins. If he could get the idea of paper money past them then he was home and, if not dry, then at least merely Moist.

'So you think these could catch on?' he said, during a lull.

The consensus was, yes, they could, but they should look 'fancier', in the words of Natty Poleforth: 'You know, with more fancy lettering and similar.'

Moist agreed, and handed over a note to every man, as a souvenir. It was worth it.

'And if it all goes wahoonie-shaped,' said Mr Proust, 'you've still got the gold, right? Locked up down there in the cellar?'

'Oh, yes, you've got to have the gold,' said Mr Drayman.

There was a general murmur of agreement, and Moist felt his spirits slump.

'But I thought we'd all agreed that you don't need the gold?' he said. In fact they hadn't, but it was worth a try.

'Ah, yes, but it's got to be there somewhere,' said Mr Drayman.

'It keeps banks honest,' said Mr Poleforth, in that tone of plonking certainty that is the hallmark of that most knowledgeable of beings, The Man In The Pub.

'But I thought you understood,' said Moist. 'You don't need the gold!'

'Right, sir, right,' said Poleforth soothingly. 'Just so long as it's there.'

'Er, do you happen to know why it has to be there?' said Moist.

'Keeps banks honest,' said Poleforth, on the basis that truth is achieved by repetition. And, with nods all round, this was the feeling of Tenth Egg Street. So long as the gold was somewhere, it kept banks honest and everything was okay. Moist felt humbled by such faith. If the gold was somewhere, herons would no longer eat frogs, either. But in fact there was no power in the world that could keep a bank honest if it didn't want to be.

Still, not a bad start to his first day, even so. He could build on it.

It started to rain, not hard, but the kind of fine rain where you can almost get away without an umbrella. No cabs bothered to trawl Tenth Egg Street for trade, but there was one at the kerb in Losing Street, the horse sagging in the harness, the driver hunched into his greatcoat, the lamps flickering in the dusk. With the rain getting to the blobby, soaking stage, it was a sight for damp feet.

He hurried over, climbed in, and a voice in the gloom said: 'Good evening, Mr Lipwig. It's so nice to meet you at last. I'm Pucci. I'm sure we will be friends…'

'Now, you see, that was good,' said Sergeant Colon of the Watch, as the figure of Moist von Lipwig disappeared round the corner, still accelerating. 'He went right through the cab window without touching the sides, bounced off that bloke creepin' up, very nice roll as he landed, I thought, and he still had hold of the little dog the whole time. Done it before, I shouldn't wonder. Nevertheless, I'm forced, on balance, to consider him a twit.'

'The first cab,' said Corporal Nobbs, shaking his head. 'Oh dear, oh dear, oh dear. I would not have thought it of a man like him.'

'My point exactly,' said Colon. 'When you know you've got enemies at large, never, never get in the first cab. Fact of life. Even things what live under rocks know it.'