The steam engine has arrived on the Disc, and Moist von Lipwig is tasked with bringing the railway to Ankh-Morpork. The most ambitious of the Industrial Revolution novels, following the railway's construction against opposition from conservative dwarfs, political manoeuvring, and the sheer difficulty of laying track. Terry Pratchett's penultimate novel, written as his health declined, and a celebration of progress, engineering, and the unstoppable momentum of a good idea.