'Didn't there use to be a deep pit full of spikes down there?' he said.

'I can't imagine why you would think that,' said Lord Vetinari.

'I'm sure there was,' Moist insisted.

'Can you recall, Drumknott, why our Mr Lipwig should think that there used to be a deep pit full of spikes behind that door?' said Vetinari.

'I can't imagine why he would think that, my lord,' Drumknott murmured.

'I'm very happy at the Post Office, you know,' said Moist, and realized that he sounded defensive.

'I'm sure you are. You make a superb Postmaster General,' said Vetinari. He turned to Drumknott. 'Now I've finished this I'd better deal with the overnights from Genua,' he said, and carefully folded the letter into an envelope.

'Yes, my lord,' said Drumknott.

The tyrant of Ankh-Morpork bent to his work. Moist watched blankly as Vetinari took a small but heavy-looking box from a desk drawer, removed a stick of black sealing wax from it and melted a small puddle of the wax on to the envelope with an air of absorption that Moist found infuriating.

'Is that all?' he said.

Vetinari looked up and appeared surprised to see him still there. 'Why, yes, Mr Lipwig. You may go.' He laid aside the stick of wax and took a black signet ring out of the box.

'I mean, there's not some kind of problem, is there?'

'No, not at all. You have become an exemplary citizen, Mr Lipwig,' said Vetinari, carefully stamping a V into the cooling wax. 'You rise each morning at eight, you are at your desk at thirty minutes past. You have turned the Post Office from a calamity into a smoothly running machine. You pay your taxes and a little bird tells me that you are tipped to be next year's Chairman of the Merchants' Guild. Well done, Mr Lipwig!'

Moist stood up to leave, but hesitated. 'What's wrong with being Chairman of the Merchants' Guild, then?' he said.