The City and the City
by China Mieville
The City and the City is an absorbing mystery, both on the mystery-mystery level and the what-the-hell-are-these-cities mystery level. Like stories of its type, it solves the superficial mystery, gives you a good sense of the background, but you know all the while that there is much Borlu doesn't tell you -- or possibly doesn't realize himself. And you know this is coming, because it's that kind of book.
Like Avice, Borlu has truck-sized blind spots. Like Avice, he gets some better, though of course it comes with a price.