RAISING STEAM, by Terry Pratchett. Doubleday, 365 pp., $26.95.
Of Terry Pratchett's hilarious Discworld fantasy novels, set on a pancake-shaped land mass carried by elephants riding a turtle through space, "Raising Steam" probably explores the most territory, from the not-quite-London city-state of Ankh-Morpork to the not-quite-France vistas of Quirm. Pratchett's books don't build on one another -- you could start with number 40 (this one), if you like -- but read more than a few of them and you'll realize that Pratchett's appeal isn't just his roller coaster plots but the depth of his ideas.
In "Raising Steam" we meet Dick Simnel, a country bumpkin blessed with a brilliant mathematical mind, who comes up with the idea for a steam engine and brings the Tolkien-meets-Wodehouse world of wizards and demons into the steam age. Trolls are enlisted to guard bridges, dwarfs are asked to smelt steel and goblins set to work on maintenance. It's all overseen by the reluctantly heroic Moist von Lipwig, a former con man press-ganged into running the whole operation by the Tyrant of Ankh-Morpork, Havelock Vetinari.
Moist is the latest and, regrettably, probably the last of Pratchett's unlikely heroes -- the author has Alzheimer's disease -- and he has become the perfect protagonist for comedy about government jobs (in "Going Postal," arguably Pratchett's best book, Moist runs the post office; in "Making Money," the mint). Here, Moist deals with surveyors who "rejected proposed routes as too steep, too waterlogged, crumbling, or occasionally flooded and, in one case, full of zombies"; he maintains his marriage to his no-nonsense wife, Adora Belle Dearheart ("Spike," to her husband), and he deals with the encroaching menace of a dwarf faction that doesn't like the interspecies cooperation encouraged by the railroad project.
"Raising Steam" is a funny fantasy novel, rewarding to both longtime readers and novices, filled with characters who leap off the page and metaphors that make you laugh out loud. When Harry King, the grimy industrialist who bankrolls the railway, gets angry, his state of mind "could only be described as volcanic: one of those slumbering volcanoes that suddenly go off pop and the calm sea is instantly awash with dirty pumice and surprised people in togas."
Looked at another way, the book is about much that is very important: London's awful 7/7 subway bombings, and fundamentalist extremism, and how hard it is to be merciful when you're in the right. Labeling it "light prose" seems unfair.
Given his struggle with a terrible neurological disease, I was prepared to allow Pratchett a victory lap after 30 years of writing so very well. But "Raising Steam" is consistently funny, wise and clever. Discworld is vanishing from Pratchett's wonderful, vigorous brain, city by city and citizen by citizen, but every time another novel goes to press, some part of that mind achieves immortality.