Detective Tyador Borlú of Besźel’s Extreme Crimes Squad is assigned to what at first appears to be a fairly straightforward crime: the murder of a young woman. Her body is found dumped in a park situated on the border between Besźel and Ul Qoma.

And right away the reader realizes that, no matter how straightforward this murder mystery might be, there’ll be nothing straight about the narrative, for Besźel and Ul Qoma aren’t merely countries that happen to border one another. They are city-states in a state of intimate balkanization.

One side of a street may be in Besźel while the other is in Ul Qoma. Part of the park is in one country, while little islands of playground are in the other. The top storey of an apartment building is in Ul Qoma, the rest in Besźel. Situated in an unnamed Eastern European milieu, the conjoined cities are ill at ease with one another and, historically, occasionally at war. Like territories in the former Yugoslavia, various areas of Besźel/Ul Qoma are disputed or not in either city.

And, of course, the murder is not straightforward. The more Borlú investigates, the more he is thwarted by the various powers of Besźel. It appears to Borlu that, in fact, the solution to the case (if not precisely the murder) is simple: the entire matter should be turned over to Breach.

Citizens of the conjoined cities do not see each other or, rather, they have learned since they childhood to “unsee” the pedestrians and motorists and architecture of the city across the border. It is illegal to see across the border, though that is hardly an enforceable crime. (And driving down the street requires a certain amount of attentive unseeing in order to avoid wrecks.) But making contact or crossing the border, except through certain corridors, is enforceable and enforcement is performed by a mysterious power called Breach. Borlú suspects that the dead woman was murdered in Ul Qoma and illegally dumped in Besźel, thus making the crime not the problem of police on either side of the border but rather the turf of Breach.

With his sidekick Corwi (for this is, in certain respects, a novel that hews closely to the terms of the police procedural genre), Borlú comes to realize that “Breach were beyond our ken or control. Whatever situation or thing this was, whatever had happened to Mahalia Geary [the murder victim], we two were its only investigators, so far as we could trust...”

Borlú must travel to Ul Qoma in order to continue his investigation. He’s been there before, but not for a long time.

Borlú has traveled to other parts of the world, as well, such as London for a conference on divided cities (Jerusalem, Budapest, and so on). One of the most fascinating aspects of The City and the City is that Miéville doesn’t create an alternate universe; the conjoined cities are right here, right now, making our quotidian world strange, alternative. Miéville doesn’t inject an alternate history upon us but absorbs us into a possible present that becomes hyper-real, reinforced by Miéville’s closely observed prose which allows nothing subjective to creep in.

In order to work in Ul Qoma, Borlú must respect local law and unsee Besźel. Fortunately, “Acclimatisation pedagogy’s come a long way with computers”:

“They sat me in what they called an Ul Qoma simulator, a booth with screens for inside walls, on which they projected images and videos of Besźel with the Besź buildings highlighted and their Ul Qoma neighbors minimised with lighting and focus. Over long seconds, again and again, they would reverse the visual stress, so that for the same vista Besźel would recede and Ul Qoma shine.”