Miéville is best known as a science fiction writer, though there's no SF to be found here. Rather, we have a police procedural, albeit one with a distinctive twist. The precise nature of that twist has been given away in far too many of the reviews and commentary I've seen about the book; I think I'd have enjoyed the first fifty pages or so even more if I'd had to figure out for myself precisely what Miéville was up to. So I'm going to do the best I can not to give away the notion that makes the book so interesting.
Our hero is Inspector Tyador Borlú of the Extreme Crime Squad in the city of Besźel, somewhere in southern Europe. His current assignment is to solve the murder of a young woman, a job that becomes much more complicated when it is learned that the murder was committed in the neighboring city of Ul Qoma and the body dumped in Besźel. The two cities -- city-states would probably be a better description -- have a complicated geopolitical relationship under the best of circumstances, but political tensions at the moment are on the upswing. Each city has a radical nationalist movement, devoted to the destruction of the other; there's also a growing unification movement that longs to see the two cities united as one.
As Borlú's case becomes an international incident, he's forced to travel into Ul Qoma to work with their police force. The investigation leads them into the the nationalist and the unification movements, the complications of the two cities' relations with other nations, and the possible smuggling of archaelogical artifacts from one city to the other. And as Borlú didn't face enough pressure, always hovering in the background is the shadowy police agency known as Breach, independent of both Ul Qoman and Besź police. Breach is tasked with only one job -- to guard the boundaries between the two cities -- and it takes that job very seriously.
If it were only a run-of-the-mill murder mystery/police procedural, The City and the City would be a rousing success. There's a nice array of potential suspects, a few terrific chase scenes, and an entertainingly intricate plot that resolves in fascinating ways. And that central plot point that should remain a surprise complicates things in all the right ways, making the chases more suspenseful, adding layers of complexity to everyone's motives, and providing a surprisingly deep layer of philosophical contemplation about the nature of boundaries, both geographical and otherwise.
This is the first of Miéville's books that I've read. My friends who are fans tell me that while they enjoy the book, they definitely think it's among his lesser work. And I'll take that as good news, because if the rest of his books are even better than this, I've got some terrific writing ahead of me.