Raising Steam (discworld, #40; Moist Von Lipwig, #3)

This novel in Terry Pratchett's Discworld series is set primarily in and around Ankh-Morpork, a sprawling city ruled by its Patrician, Lord Vetinari, who maintains order through intelligence and political manipulation.

Dick Simnel, a young engineer from the small town of Sheepridge, has spent years perfecting a steam-powered locomotive. His father died in a boiler explosion when Dick was ten, and the boy vowed to master the force that killed him. After his mother, Elsie Simnel, a midwife, moved them to the nearby city of Sto Lat, Dick discovered mathematics in a library and used a sliding rule and meticulous calculations to succeed where his father's instincts failed. Funded by gold his pirate grandfather left behind, he builds first a working prototype and then a full-size locomotive he calls Iron Girder. He takes Iron Girder to Ankh-Morpork, where he demonstrates it to Sir Harry King, a wealthy sanitation magnate eager for a more respectable enterprise. Harry agrees to bankroll the railway, and the two hire Mr. Thunderbolt, a diamond troll lawyer, to formalize their partnership.

Vetinari, recognizing the locomotive's potential to transform commerce and politics, assigns Moist von Lipwig to oversee the venture on the city's behalf. Moist, a reformed con man who serves as Postmaster General, Deputy Chairman of the Royal Bank, and Master of the Mint, is a gifted negotiator and showman. Thunderbolt structures the enterprise so that Harry and Dick hold the major shares while the city holds a small casting-vote share under Vetinari's control. Moist begins negotiating land rights with landowners along the proposed route to Sto Lat.

While the railway takes shape, a parallel threat builds. Extremist dwarfs called grags, religious fundamentalists who reject modernization and interspecies cooperation, attack clacks towers, the semaphore communication network connecting the continent. The clacks is run by Moist's wife, Adora Belle Dearheart, whose workforce of goblins, recently recognized as sapient beings, have revolutionized the system. The grag attacks represent a broader rejection of the Koom Valley Accord, a fragile peace treaty between dwarfs and trolls. In the dwarfish homeland of Uberwald, a radical grag named Ardent agitates against the progressive policies of the Low King of the Dwarfs, Rhys Rhysson, while Rhys struggles to hold together a fractious council. Albrecht Albrechtson, a respected traditionalist who had once been Rhys's rival, surprises the council by pledging his full support for the King against the extremists.

The Grand Opening of the Ankh-Morpork and Sto Plains Hygienic Railway is a triumph. Dick handles hostile press questions with plain-spoken honesty, the train crosses its first bridge, and it arrives in Ankh-Morpork to cheering crowds. Moist further burnishes the railway's reputation by diving under Iron Girder to save two toddlers who have wandered onto the tracks, nearly dying in the process. He pushes Harry to implement safety measures and proposes tiered classes of carriage to broaden the railway's appeal.

Moist negotiates the extension to the neighboring city-state of Quirm, routing the line through an uninhabited wasteland called the maquis after local landowners refuse to sell. Harry personally leads a raiding party to clear the bandits infesting the area. When dwarf delvers ambush Moist at the railhead and massacre railway workers, Moist kills three dwarfs in a frenzied battle, aided by a goblin war potion. Commander Vimes of the City Watch warns Moist that grags have placed him on a hit list.

Iron Girder appears to develop a kind of sentience. When a dwarf saboteur breaks into her shed, the locomotive kills him with a blast of live steam. Dick admits he cannot explain the phenomenon but acknowledges that people treat Iron Girder as though she is alive. The railway expands across the Sto Plains, the Quirm line is completed, and fresh seafood arrives in Ankh-Morpork for the first time without spoiling.

Vetinari orders Moist to build an express line all the way to Uberwald, over twelve hundred miles away, citing unspecified political urgency. Harry is reluctant, but Moist persuades him by suggesting he sell shares to spread the risk. Construction accelerates, with gangs of workers, trolls, goblins, and golems laying track day and night.

The crisis arrives when Ardent stages a coup in Schmaltzberg, the dwarf stronghold in Uberwald, while the Low King attends a summit in Quirm. Lady Margolotta, the vampire governess of Uberwald, alerts Vetinari by clacks. Vetinari orders Moist to collect the Low King and transport him back to Uberwald by train. Iron Girder, now armored with a new alloy called sorortanium, departs with the King's party aboard, including Commander Vimes, troll Sergeant Detritus, and a squad of watchmen. A decoy coach sent by road draws off grag assassins.

The journey is harrowing. Moist identifies and neutralizes grag spies on the train. At the Paps of Scilla, a treacherous mountain pass, grags bombard the train with boulders, but Iron Girder's sorortanium armor deflects them while trolls and goblins fight back. A decoy engine called the Flyer, sent ahead of Iron Girder, is derailed and its boiler blown up as a trap; the King's sharp night vision spots the wreckage in time. Grags destroy water supplies and murder railway workers along the route. In the canyons near Uberwald, attackers uncouple the guard's van, but Constable Bluejohn, a troll on the Watch, holds the cars together by gripping the buffers. Moist and Vimes fight grags on the train roof, while a mysterious stoker on the footplate defeats attacking dwarfs with lethal efficiency.

At the gorge of the Wilinus Pass, the bridge is not yet strong enough to bear the train's weight. Moist has secretly deployed ancient golems, clay automatons belonging to the city, to reinforce the structure from beneath. Iron Girder crosses the gorge, seemingly flying through the mist, and the bridge collapses behind them.

Iron Girder arrives at Bonk, the human city adjacent to Schmaltzberg. The coup has already begun to unravel: Ardent's supporters are wavering, and Albrecht Albrechtson has remained defiant in his dungeon, where a goblin courier taught him humility during his imprisonment. Rhys enters Schmaltzberg with armed supporters and sentences the captured Ardent to trial before a jury of his victims' families, demonstrating the modernized justice the King champions.

Then comes the greatest revelation. Rhys announces that the Low King is, in fact, female, and will henceforth be known as the Low Queen. The Queen challenges anyone to deny her right to the Scone of Stone, the sacred coronation seat whose possession confers legitimacy on the ruler of all dwarfs. No one does. Albrechtson shouts his support, and the assembly falls in line. The Queen also announces her pregnancy and her marriage to Aeron, her secretary.

Back in Ankh-Morpork, Vetinari presides over a ceremony of honors: Harry becomes Lord King of the Permanent Way, Dick is knighted, and medals go to everyone who served on the train, including goblins. Vetinari privately reveals to Moist that he himself was the mysterious stoker on the footplate, having disguised himself as a man called Stoker Blake to join the journey, and warns Moist never to speak of it. On the eve of departure from Bonk, Moist visits Iron Girder alone and hears her voice: She declares herself an idea made real by belief, a goddess of steam whose children will be even more powerful. A goblin presents Vetinari with a pedal-driven two-wheeled velocipede, and Vetinari reflects that the world keeps changing, and all anyone can say is: What next?