Moist looked around and saw that they were surrounded by goblins sitting quietly in a big circle like worshippers at the shrine, and once again Dick Simnel said, ‘Power, Mister Lipwig, power under control.’

Moist was seldom speechless, but this time all he could say was, ‘Good luck with that, Mister Simnel. Good luck.’

And the driver made his magic and the fire box opened and spilled dancing red shadows all around the footplate. And then came the rattle and jerk as Iron Girder took the strain and breathed steam for one more turn around the track as the goblins whooped and cackled and scrambled up her sides. And then came the first chuff and the second chuff and then the chuff bucket overflowed as Iron Girder escaped the pull of friction and gravity and flew along the rails.

Dick Simnel lit his pipe from a hot coal and said to the night, ‘Aye, gradely.’

When Drumknott entered the Oblong Office a few days later there was a familiarity to the silence, interrupted only by the scratch of a pencil as the austere figure behind the desk filled in a word on that day’s crossword. Drumknott coughed.

‘Yes?’

The face of the Patrician was forbidding. An eyebrow shifted quizzically, a characteristic known and feared by many. Drumknott smiled.

‘Many congratulations! You have that expression down to a T and the accent never faltered. And, of course, the frown! You’ve always been very good at the frown. Quite frankly, if he was standing next to you I wouldn’t know whom from which.’

Suddenly the face of the Patrician disappeared, leaving only Charlie the Clown in Lord Vetinari’s clothes, looking embarrassed.

‘It wasn’t very difficult, Mister Drumknott, with you giving me those little signs and everything.’

‘Oh no,’ said Drumknott. ‘Your performance was perfect. You’ve impersonated his lordship for two weeks and not put a foot wrong! But now to business. The sum we agreed will be deposited in your special account at the Royal Bank tomorrow.’ Drumknott smiled again and said, like a cheerful uncle, ‘How is your wife these days, Charlie?’

‘Oh, Henrietta’s fine, Mister Drumknott, thank you for asking.’

‘And your little boy – Rupert? He must be out of school now, yes?’

Charlie laughed uncertainly and said, ‘Not so little, sir, he’s growing up like a weed and wants to be an engine driver.’

And Drumknott said, ‘Well now, Charlie, you already have enough money to put him through a trade anywhere in the city and give your daughter a dowry fit for a queen. And, of course, you’re still in the same house? Excellent!’

‘Oh, yessir, and thanks to you we’ve got much better bedrooms for the kids now and are saving up for a granny flat for when we can afford a granny. And Henrietta is overjoyed at the amount of money I’m bringing in these days and can even afford to get her hair cut at Mister Fornacite’s, just like the posh ladies do. She’s over the moon about it.’ He grunted and said, ‘I don’t earn that much from the puppet shows and clowning business.’