Flushed with the thrill of the ride, Moist dropped back down into the guard’s van, still empty except for the sleeping form of Detritus. He smoothed down his hair and wiped the smuts from his face, and wandered out of the carriage, a smile on his face.

Down the length of the train the lights were going out when Commander Vimes reappeared from his latest sortie and headed for the coffee.

‘The King and his council of war are making their plans,’ he said. ‘Your latest clacks reports and what I hear from let’s call them observers on the ground suggest that work on the rails is going ahead reasonably happily.’

He looked slyly at Moist. ‘Pretty soon, it seems, Mister Lipwig, you’ll have to put your money where your mouth is. Oh, and another thing. Here’s a flimsy from your good wife. Even with the news of the Schmaltzberg coup spreading, there appear to have been very few attacks on clacks towers outside Uberwald.’

Taken aback, Moist said, ‘Well, that is good news.’

But Vimes just frowned and said, ‘Don’t get excited. I’d wager that there are still some out there who’d knock over a clacks tower even if they saw Tak on the top of it. That’s the trouble, you see. When you’ve had hatred on your tongue for such a long time, you don’t know how to spit it out.’

Moist had made sure, oh bliss, right from the start that he would have a sleeping compartment of his own, but, unlike those in the First Class sleeper carriage, his was more utilitarian and using it was an exercise suited to people who like toying with twisty cubes and other notorious playthings. It had a folding bed, which folded down and hit him on the head, and a washbasin into which his toothbrush would just about fit. But there was a sponge provided, and since he was suitably athletic he made the best of it, ending up if not clean, not any dirtier either. And gods, he was tired, and whatever it was that drove him seriously needed a rest, but the mind was its own worst enemy and the more he tried to get himself lulled by the rhythms of the railway, the more his niggling thoughts seemed to burgeon like a cloud.

They had been lucky so far – only the two grag spies to deal with, and pretty poor spies at that – but sooner or later the rat would surely be out of the bag and the grags would know that Rhys was on board. Simnel’s hope seemed to rest on the fact that they would be using Iron Girder by that time. But could she really make a difference, Simnel’s little experiment, more used to giving children rides around the yard? I’m sure that when that locomotive of Simnel’s first arrived, Moist thought, it was pretty small and I wondered how it could go the distance, even to Sto Lat. But now she seems so powerful. And the way Simnel keeps upgrading her and paying her attention, it’s as if something bad would happen if she wasn’t the queen of the yard. She never sleeps. There’s always that little hiss. That little tinkle of metal. Mechanical susurration, whether or not she is ostensibly running.