I read The City and the City by China Mieville yesterday, the book my sister got me for my birthday last year from Barnes and Noble with their mystery packaging.
It's a very interesting story: It takes place in a not-precisely-defined southeastern European territory that is occupied by two cities in the same place. The cities aren't side-by-side, they're actually in the same place: They claim different streets and buildings, sometimes even different rooms in the same building and different trees in a park, and govern them as independent territories. People who live in one city have to "unsee" the other, they don't acknowledge the people and places that are "in" the other city unless they actually go to the other city: Travel to the border, get their passport stamped, go through customs, etc. They might wind up literally back on the same street as they started, but now they don't see the city they came from. Mail has to go through customs, phone calls go through an international exchange, etc. One character recalls the time that a building next to his home caught on fire and he had to watch the story on the news, even though he could see the flames from his window.
An organization called the Breach enforces this separation, and will take you away if you so much as look at and acknowledge the person next to you on the street from the other city.
The rest of the world is, by all accounts, normal, and is either bemused or contemptful of this setup.
Besźel, where we are first introduced, is an economically stumbling ramshackle mess, while Ul Qoma, the other city, has a booming economy from an archaeology and technology boom despite being under an embargo from the United States.
The story opens with a murder and investigation by Inspector Tyador Borlú of the Extreme Crime Squad in Besźel, who eventually has to go to Ul Qoma, and the investigation uncovers the possible existence of a third city. Orciny, which most people dismiss as an urban legend or joke. A hidden city that is secretly controlling the other two, existing in territory that each city believes belongs to the other, influencing what happens to people and organizations alike. Perhaps with advanced technology, maybe with magic, but certainly with unearthly control given what they can do...
The twist (SPOILERS, of course):
There is no third city. There is no ancient conspiracy. No magic or secret advanced technology (...probably. There are some archaeological questions that are never quite answered). Just ordinary criminals (A corrupt city councilman, some right-wing nationalist street thugs, and a discredited archaeologist) running a smuggling operation to indulge what seems to be the whims of a foreign CEO who is poking some myths about ancient technology. It's pretty much the behind-the-scenes story of Ancient Aliens if the show had never been officially granted access to some of the places they went, so they tricked some gullible college students into believing they were on to something real and had them smuggle artifacts for them.
The organization Breach, which does exist, doesn't have supernatural powers either. They're just your run-of-the-mill secret police, except that since they move "between" cities and everybody takes such pains to not notice people not in their city, that means that people literally don't notice them. Hence, they seem to be invisible. Their access to both Besźel and Ul Qoma information means that they know things which seem like magic to people living in one city or the other.
I wonder if there's going to be any kind of follow-up?