‘You will see to it, won’t you, Mother, that they leave in time for the Zemphis express?’

And she did, after a bowl of porridge, hot and sugary, just the kind Adora Belle totally disliked. Moist could feel it sticking to his bones as he and the King, smiling and rejuvenated after their nap, left the haven of Mrs Simnel’s little house as the sun began to rise over Sto Lat.

In a cavern somewhere near the gloomy, somewhat twisted metropolis of Slake the grags were discussing the railway menace, and ways of stopping it. They had found an artificer who liked working iron, and since he was a dwarf from Ankh-Morpork he was in a position to explain matters to them.

Sitting nervously in the dimly lit cavern and trying to appear to be very much on the side of the grags while, of course, being on the side of the money, the artificer explained that locomotives are heavy, and derailing them might be best left to when a train was heading through gorges or near the mountains. And he suggested that an alternative would be to deprive the engines of the basic necessities – fuel and water – and then attack them when they were most vulnerable. He had fortuitously come across a map that showed the locations of all the coal bunkers and water cranes and towers, and this he now produced.

‘And just supposing we set our sights on stopping a particular train … how many people do we need to take down these … water cranes?’ croaked an anonymous grag in the darkness.

‘You’ll need plenty of you on this,’ said the helpful dwarf. ‘The opposition is probably bright enough to realize that you’ll be focusing your efforts on disabling the engines, and will have the cranes and bunkers well guarded. Of course,’ he added, ‘when you’re up high in the mountains you have the advantage on ’em.’

The artificer looked hopeful after this, in so far as he could be seen in the dark cavern, and said, ‘Well, that’s about it, sirs. It’s not very difficult, but you know where to contact me if you need me.’

In truth, the cavern was giving him the heebie-jeebies, and he wanted to be out of there as soon as possible. He heard the voice of the leader saying, ‘Well done, my friend. Please take this gold as a token of appreciation and, yes, we do know where to find you and every member of your family as well.’

The artificer looked into the heavy leather bag and was delighted. ‘Very kind of you, sirs. I hope to help you again at some time in the future.’

And he went away happy with such big wages for so little real work. The grags didn’t know anything! It was like taking money off children, but he kept smiling and said goodbye and had his throat cut in the darkness by a delver before he’d even left the dripping chamber. After all, what grag would hand over gold to an Ankh-Morpork dwarf? To a grag they were all unbelievers.