I found it hard to get started with this book. Part of it was my incredulity with the premise that a city can exists in the same space as another city. After reading other GR reviews, it turns out that this is a common aspect of Mieville novels. The other part was that I was a Mieville virgin, in the sense that this was the first book of his I had ever read.
But it grew on me, this book. Noir and police detectives, quite a throwback, but effective. Once I was past the improbable premise, it was intriguing enough. By the time the book came to the third co-existing community, disbelief had given way to enjoyment with the good story-telling.
The ending was nice, though a non-SF style resolution. 4 stars.