Young Simnel smiled and said, ‘That’s very thoughtful of you, Sir Harry. Perhaps I should give them a message to take to my mother. She’ll show them where everything is. My dad said always put a few nasty little booby traps around the place before you lock up and then after that owt they can steal from you they’re welcome to, if they’ve still got their arms to carry it away, that is.’

Harry laughed out loud and said, ‘Sounds to me like your old dad looked at things just the way I do. What’s mine is mine and what is mine is me own.’

When Moist and Mr Thunderbolt stepped out into the compound Moist saw that people were still queueing up for a ride on the train, which was waiting like a queen while Mr Simnel’s lads filled her bunker full of coal, and oiled and greased everything again, including themselves. They tapped her wheels and polished everything that could be polished, once again including themselves, while just about every little boy in the city, and, amazingly, most of the girls, stared at her in awe, worshipping at her shrine. And then it came back to him: earth, air, fire and water, the sum of everything! The goddess had found her worshippers.

There was a sound like thunder, but it was only Mr Thunderbolt clearing his throat to say, ‘Remarkable, isn’t it, Mister Lipwig? There appears to be what one can only call a presence of sorts, a hint, as it were, that life turns up in many different guises, perhaps? Just a passing thought.’

Moist had never heard such clear diction from a troll, and it must have shown, because Thunderbolt laughed, saying, ‘A touch of diamond does the trick, Mister Lipwig, and I will endeavour to draw up contracts that suit all parties, you need not worry.’

Just then Moist beheld Drumknott, greasy and cheerful and covered with smuts, stepping off the engine and regretfully handing a hat and a very grubby jacket to one of Mr Simnel’s lads. Moist grabbed the little secretary by one arm.

‘Where did you get to, Mister Drumknott? I’ve been looking for you everywhere,’ he lied. ‘His lordship is expecting you back any time now.’

Moist wasn’t sure he liked Drumknott, but it wouldn’t do to have him as an enemy, being so close as he was to the engine that drove Ankh-Morpork, and so he cleaned up the little man as best he could and flagged a coach back into the city, noticing, as they travelled along the busy towpath, that the major traffic was still going the other way.

Moist knew about the zeitgeist, he tasted it in the wind, and sometimes it allowed him to play with it. He understood it, and now it hinted at speed, escape, something wonderfully new, the very bones of the land awakening, and suddenly it seemed to cry out for motion, new horizons, faraway places, anywhere that is not here! No doubt about it, the railway was going to turn coal into gold.