A children's book, published in 2002, which is the first novel written by Philip Reeve.
The story is set in the far future, when cities are mobile, moving around the world on huge tractor wheels, gobbling up smaller cities. An orphaned boy dreams of excitement and gets it, becoming embroiled in saving the world. Written very much in the "steampunk" genre (cyberpunk with gears and victorian behaviour, see Gibson and Sterling's The Difference Engine, or Alan Moore's The League of Extraordinary Gentleman), but aimed at young readers, it reminded me of the best aspects of Northern Lights, the first book in Phillip Pullman's His Dark Materials trilogy. There's a brave innocent boy and a brave innocent girl (who, as in Northern Lights, also has a father with dubious intentions). But Mortal Engines has dirigibles, pirates who want to be posh, spies, a Tin Woodman cyborg assassin, a girl with a face cut in half, a city in the sky, and the cities on the move. The main city is London, piled up high instead of spread out, and split into an extremely stratisfied class system similar to Victorian England.
Books where the main characters want adventure, get it, and strive to survive through it, all the while wondering why the heck they wanted adventure in the first place, are my cup of tea. 'May you live in interesting times', goes that old curse. It's a common theme -- the reluctant hero with dreams -- from The Hobbit to Gilliam's Brazil, and my favourite, letting me always wonder "what would I do?" and thinking about interesting times I've had, and how I survived.
I read this on the train down and back from London recently, which had the pleasant side effect of adding to the reality of reading about moving cities, especially as I went by the low tide mud flats at Manningtree, mirroring the muddy desecrated tracks made by huge cities. Once we were rolling into Liverpool Street Station, with the rumbling echo between brick graffiti'd buildings, I was spinning in and out of the imagined world and the real. There was also a 'mirror' of the London Underground in the book, only instead of a train it was an elevator, filling with the crowds of city people, racheting down the levels of the city, and again, reading this while on the Tube, rocking towards Tottenham Court Road, I grinned at the parallel.
Mortal Engines is one of those books I know I'll reread a few times when I want a good old escape into imagination, into adventure and the struggle to be brave.