For those who don't know, this book is about a detective working in a city which interlocks geographically with another city in another country, and both populations are enjoined to ignore the people in the 'other' city, walking past them without acknowledging their existence. Everyone obeys more or less consistently, and occasional infractions are harshly punished.
At the moment I am working 'in purdah'. That means we are not allowed to do any actions, or issue any words, which support one political party over another. I dreamed I was at work in purdah, editing a document to remove any references to the other city. Thus the story was integrated into my unconscious mind and I could finish it.
People often say the point or litmus of quality of science fiction is a 'sense of wonder'. I think the true point of it, beyond transient entertainment of the hour, is to slap your face and wake you up. That is, 'Notice your life for once'. For instance, experience the gravitational field you are walking through, which you don't even think about any more (or whatever: experience the fragility of your flesh, the chaos of your mind).
I think the City and the City works as very versatile social metaphor, slapping you to notice the consensus by which we maintain the social order which oppresses us. The actual development of the plot is a little depressing and constrictive, embodying Mieville's frustration as a revolutionary socialist, that the enforcement of oppression is too weak to maintain it, and it is only our self-policing that keeps us from being free. But the sanctions are also harsh and real.
I was reminded of the article by Christopher Hitchens about Animal Farm in the Guardian on Saturday. He quotes Orwell:
I saw a little boy, perhaps ten years old, driving a huge carthorse along a narrow path, whipping it whenever it tried to turn. It struck me that if only such animals became aware of their strength we should have no power over them.
The whip is real, but it is not sufficient. I was watching The Bourne Supremacy a couple of nights ago, and there's a scene where the Brian Cox character is berating Pam Landy, and everyone else in the office is ignoring them. When she turns to her subordinates and speaks to them directly, giving them orders, they can see and hear her. I've always been struck by that scene, and reading this book made it more vivid.
So, I think this is a book which extrapolates a very rich and flexible metaphor, which illuminates and wakes us to lived experience in the way that SF should. I personally still find the style rather cold and controlled, and although I am glad to have read it, I didn't think it was that enjoyable as literature. But I would say worth persisting at for those who like me found it hard to penetrate. I imagine it will be remembered and reread in decades to come.