Moist thought about whoever it was who had got into the compound to smash her up, who ended up dead, dead, dead. Wild steam from a train that wasn’t running. Earth, fire, wind and rain all in one element of speed. And slowly Moist shut down, although a part of him was always listening to the rhythm of the rails, listening in his sleep, like a sailor listening to the sounds of the sea.

As Moist slept, the train barrelled like a very slow meteor through the night, climbing up through the Carrack Mountains. Almost the only light to be seen with the moon under a cloud came from the engine’s headlamp and the glow from the furnace when the door was opened to shovel in more coal.

The engine stokers of the Hygienic Railway were a breed apart: taciturn, perennially grumpy, seemingly only willing to talk to the drivers. In the unwritten hierarchy of the footplate the drivers were at the top, of course, and then the stokers and after the stokers there would be the wheel-tappers and shunters: lesser beings but acknowledged as useful. At times it appeared that the stokers considered themselves the most important component of the railway, keepers of its soul, as it were. When off duty they all messed together, grumbling, puffing their wretched pipes, and talking to nobody else. But shovelling coal all day built muscles of iron, so the stokers were strong and fit, and sometimes between shifts there were sparring matches with shovels, with the combatants cheered on by their fellows.

In fact, one of the stokers on the train was a bit of a legend, according to the others, although Moist had not come across him yet. Stoker Blake was said to be death on legs if he was aroused. The other stokers were fierce fighters, but it was claimed that none of them ever got to touch Stoker Blake. A stoker’s shovel, incorrectly used, was an illustration of Commander Vimes’s dictum that a workman’s tool used cunningly could give the average watchman a real headache.

And so the stokers laughed and danced as they sparred with their shovels and got drunk – but not when they were going to be on the footplate. They didn’t need telling about that.

Tonight, cocooned from the cool wind that flew around the cab, Stoker Jim said to the train driver, ‘Here’s your coffee, Mick. Fancy a fry-up?’

Mick nodded without taking his eyes off the track ahead and so Stoker Jim carefully reached out and fried a couple of eggs on the back of his shovel, courtesy of the fiery furnace.

The houses hastily built for the railway workers were close to the water cranes and coal bunkers so that an eye could be kept on the precious coal and water supplies. They were quite small, which put some strain on the accommodation when there were children and grandparents as well, but everyone said that it was twice as good as what might be found in the big city and, after all, you were out in the fresh air, at least in between locomotives.