When Richard Simnel invents the locomotive, it's Steam Engine Time in Ankh-Morpork, the greatest city of the Discworld! With financial backing from Harry King, King of the Golden River and Moist von Lipwig, the Disc's wiliest civil servant, everyone and everything is on the move. A bid to get seafood that's still fresh spawns the tourist industry. But where there's change, there's people who don't want to change, and the budding rail has to fend off attacks of Deep Dwarves.
As a story alone, this is solid material, but Terry Pratchett remains one of the greatest living satirists. (He's also better than quite a few who are dead.) With Raising Steam, he looks at societal change driven by technology bringing people together. At the same time, it's an homage to rail culture, engineers and all the people who make the transportation industry go. It's also a blistering indictment of people who try to burn the world down rather than letting their neighbors move on with the times. "Tak does not require that we think of him, but he does require that we think."
At the same time, Raising Steam is also clearly the book of a man struggling with Alzheimer's. It remains a wonder that Pratchett can still write at all, much less as well as this. His earlier books may have been stronger (a few plot threads appear and vanish in Steam, never to be seen again), but it's still a gem. Written with the understanding that any book he turns out could be his last, he gives us a chance to check in with old friends throughout. The Discworld may be a long-running series, but every book stands alone while providing bonuses for the fans who have read the books that came before.
Raising Steam is a reminder that big things often start with little things. Here they start with a load of octopus on a midsummer's day.