They say that the only certainties in life are Death and taxes, but this is not strictly true. Death is a certainty. Taxes are more of a negotiation, conducted over centuries, between people who have money and people who would like to count it, and like all the best negotiations it is won by whoever can stay awake the longest.1

In Ankh-Morpork, the people who had money had been winning for approximately four hundred years.

It was three o'clock in the morning, and Moist von Lipwig was on the roof of the Royal Bank of Ankh-Morpork, which he ran, attempting to break into it.

He was aware that this was, technically, unnecessary. He had keys. He had, in fact, all the keys, including the big ceremonial one made of gold that was too soft to actually turn in a lock and was therefore, in Moist's professional opinion, the most honest object in the entire building. But keys were for people who had given up, and Moist had discovered that if he went too long without hanging off a parapet by his fingertips, parts of his brain began making suggestions. Last month one of them had been why not take up watercolours? and he had broken out in a cold sweat and gone straight up the drainpipe.

The skylight catch yielded to a hairpin and a lifetime of bad habits. Moist lowered himself into the darkness of the counting house, dropped the last six feet in silence, landed like a cat,2 and found the lamps already lit.

Lord Vetinari was sitting at the chief cashier's desk, reading a ledger.

'Ah, Mister Lipwig,' said the Patrician, without looking up. 'Punctual to the minute, I see.'

There were many possible responses to this. Moist's brain sorted through them at the speed of terror and rejected, in order: I can explain, this is not what it looks like, and I was just leaving, on the grounds that all three were the verbal equivalent of signing a confession in advance.

'You can't possibly have known I'd come in through the roof tonight,' he said instead.

'No,' Vetinari agreed pleasantly. 'But I knew you would do so eventually, and Drumknott finds the night air bracing. We have been here on alternate Tuesdays since February. Do sit down.'

Moist sat. It was that or fall down, and sitting had better resale value.

'The bank prospers,' said Vetinari, turning a page. 'The Post Office runs like one of Mister Simnel's locomotives, which is to say noisily, but in the correct direction. The railway reaches Quirm, Sto Lat, and, I am told, parts of Uberwald that were previously accessible only by mule and pessimism. You have, Mister Lipwig, run out of things to save.' He looked up. 'How are you sleeping?'

'Badly,' said Moist, before he could stop himself.

'Capital. A man who sleeps well is a man who has stopped paying attention.' Vetinari closed the ledger with the gentle finality of a tomb door. 'Tell me, what do you know about taxation?'

The word landed on the desk between them and sat there, like something the cat had brought in. Moist regarded it with the expression of a man who has been shown a snake and asked if he would like to hold it.

'It's what happens to other people,' he said carefully.

'An answer which is, I am sorry to say, both witty and the official fiscal policy of this city,' said Vetinari. 'Walk with me, Mister Lipwig.'

They walked. Behind them, at a distance calculated to the inch, came Drumknott, carrying a lantern and a folder. The folder was thin. Moist had learned to fear thin folders. Thick folders meant a problem someone had worked on. Thin folders meant a problem that was about to become yours.

'The Taxation Office of Ankh-Morpork,' said Vetinari, as they crossed the echoing marble of the banking hall, 'is administered by the Most Ancient and Honourable Guild of Assessors. They are very thorough. Last year they assessed, measured, and taxed every window in the Shades.'

'The Shades,' said Moist. 'Where the houses don't have windows.'

'They have holes,' said Vetinari. 'A hole, the Guild ruled in the Year of the Ambiguous Newt, is a window in a state of anticipation. Meanwhile, the Vortin family — whose residence on Scoone Avenue has, I am reliably informed, one hundred and eighty-two windows, a ballroom, and an ornamental lake with its own weather — paid four dollars and thirty-one pence last year. The assessment notes that the property is "a hovel, much decayed."'

'Someone's being paid not to count,' said Moist. It was out of his mouth before he'd decided to say it, which was how he knew it was true. It took one to know one. It took, in fact, one to know several hundred, which was approximately the size of the Guild's senior membership.

'Mister Lipwig, I am shocked by the suggestion,' said Vetinari. 'Shocked that it took you eleven seconds. You must be tired.'

They had reached the doors. Vetinari stopped, and turned, and there was a glint in his eye that Moist had seen before — once over a postal service, once over a mint, once over a railway — and which he had come to think of, privately, as the harpoon.

'The city is rich, Mister Lipwig. Richer than it has ever been. Dwarfs bank here. Goblins invent here. A troll owns three blocks of Sator Square and rents one of them to the Thieves' Guild, which I believe counts as irony. And yet the Treasury — ' he paused, ' — leaks. Not dramatically. Respectably. The money is not stolen, you understand. It simply never arrives, in the manner of a relative who is always just setting out. I require a man who can make it arrive. More than that, I require a man who can make people want it to arrive.'

'Nobody wants to pay taxes,' said Moist.

'Nobody wanted to use the Post Office,' said Vetinari. 'Nobody trusted paper money. You sold them stamps and they queued to lick the back of your head, Mister Lipwig. You are the finest liar in this city, which is why you are the only man I would trust with the truth. The truth being,' and here he extended one hand, and Drumknott placed the thin folder into it like a nurse handing over a scalpel, 'that civilization is the longest con of all. Millions of strangers, paying in advance, for streets they will never walk and watchmen they will never meet and a future they will not live to see. It is magnificent. It is the only game truly worth running.' He held out the folder. 'I am offering you the bank.'

'I have the bank.'

'The other bank. The one everyone is a customer of, whether they have signed or not.'

Moist looked at the folder. Some men are tempted by gold, and some by power, and these are the cheap seats. Moist von Lipwig was tempted by difficulty, and Vetinari knew it, and Moist knew Vetinari knew it, and the folder hung in the air between them like the last card in the deck.

'And if I refuse?' said Moist, because the script demanded it.

'Then you will return home to your wife, your bank, your railway, and your watercolours,'3 said Vetinari, 'and live a long, safe, and prosperous life, and we shall never speak of this again.'

It was, Moist reflected, the most dreadful threat he had ever received.

He took the folder.

'There is one more thing,' said Vetinari, as the great doors swung open onto the pre-dawn grey of Sator Square, where the lamplighters were going round extinguishing the night shift. 'The Guild's chief assessor is a gentleman by the name of Albright Slope. He has held the post for forty-one years. Nine tax reformers have been appointed in that time. Mister Slope has attended all nine funerals. He sends,' Vetinari added, settling his cap, 'a very good wreath. Do not let me detain you, Mister Lipwig.'

In a grey place beyond the walls of the world, where there is no time because time would be untidy, something noticed.

It did not have eyes, but if it had, they would have narrowed.

One said, They have invented assessment.

One said, Impossible. Assessment is ours. The universe is enumerated. The universe is filed.

One said, Nevertheless. In the city. They count, and they record, and they require the forms to balance. They have invented auditing.

There was a pause, insofar as there can be a pause where there is no time. Then:

One said, This is a trademark violation.

One said, Worse. They do it incompletely. There are exemptions. There are allowances. There are — and here the thought shuddered through the greyness like a crack through ice — discretionary categories.

One said, Then it is agreed. The city's accounts must be inspected.

One said, All of them?

One said, All of them. Beginning with the unlicensed exemption at the root of every irregularity. The one they all claim. The one none of them can produce a permit for.

One said, Which is?

One said, Being alive.