He peered out of the window. Perhaps it was his imagination, but the Forest of Skund seemed to get blacker the closer they came to it. The forest was worse than the maquis. From what Moist remembered, the trees stood shoulder to shoulder. And if you thought that trees didn’t have shoulders, you hadn’t been to the Forest of Skund. It was one of those places where the magic hadn’t been cleaned out yet. And some of the old fears and fancies still hung around the place. Nobody went in there until they had to, the occasional woodcutter for a bet, perhaps. It was a dark place, staring out across the plain and biding its time. Not a place to go if you didn’t want a wizard dropping on your head. If a landscape could growl, that was the Forest of Skund.

Moist took the opportunity to look at the instrumentation in the van. There were two guards on the rota for this journey, and though the train couldn’t be driven from here, the guard could at least stop it – a fact worth knowing.

As dusk fell, the sound of Detritus’s snoring lessened from somewhere in the vicinity of badgers fighting to the death to a low rumble, which caused the rest of the van to resonate. There was a fascination in watching a chest made of stone move. Not for the first time Moist marvelled: They are stone and we are told that stone lives; and once again his thoughts harked back to Iron Girder, and, to his amazement, he stopped worrying: horses, trolls, golems, engines, well, where was the downside?

He looked around him. Apart from the sleeping Detritus the guard’s van was for once totally empty. The rest of the train’s occupants were settling down for the evening elsewhere, busy with their own affairs; Commander Vimes was making his rounds of the carriages.

Moist moved quickly, no longer able to fight the little devil inside him. After all, he reasoned, he’d waited long enough to do this, and he might not have another chance. It was still light enough. He opened the door of the guard’s van, and, gripping the side of the carriage, climbed out, kicked shut the door behind him and clambered on to the top of the train. Once there he scrambled to his feet, and then, throwing caution to the winds, Moist danced on the top of the train, leaping from carriage to carriage, listening to the train’s rhythm, moving his body to accommodate it and feeling the engine and the moods of the railway until it seemed that he could understand it. It was a benison, a gift. It was a thing that could be courted but, he expected, it wouldn’t allow too much familiarity. It enthralled him and he thought: steam is not to be taken lightly.

Once, he heard a shout of ‘Oi!’ from below and Moist was no stranger to ‘Oi!’. He leaned down and said, ‘Moist von Lipwig. I’m doing a little test.’ He could hear the ‘Oi’ voice grumbling, and let it grumble because this was what he had wanted as soon as he had seen the new Flyers.