The City & The City: the book by China Mieville, and the television adaptation produced by the BBC

Spoiler warning. I'll assume familiarity with the central conceit.

The City & The City seems obviously unfilmable, so I was intrigued to learn that the BBC tried anyway. It turns out that they did not disprove its unfilmability.

The book's plot, essentially murder mystery and police procedural, is reasonably interesting in itself, but mostly it serves to lead the reader through the unique setting: two cities in two nations, each with its own identity, language, and laws, rigorously maintaining their separation even though they happen to share much of the same geography, and the social systems (moral, legal, belief) which allow this to endure. So I didn't mind so much that the television adaptation played loose with the plot. The material they added in was unoriginal -- flashbacks to a conveniently echoing case of the main character's ex, giving the star plenty of excuses to grimace anguishedly as seems to be his forté; mundane gunplay and artificially tense confrontations -- but I could forgive that. My problem with it was rather that they oversimplified the way the cities interact in a way which quite destroyed the believability. After watching it, I was left wondering how I could ever have found the idea plausible, until I reread the novel and saw how thoroughly they'd debased the concept in translating it to the conventions and limitations of film.

A crucial feature of the cities is crosshatching. A street in Besźel and a street in Ul Qoma, each with their own names, identities, and buildings, may share the same physical road. In the adaptation, this is presented as one side of the street being in Besźel while the other is in Ul Qoma. This makes it easy for the viewer to get the idea, with simple blurring to unshow the city we're not currently in. Another shot has a plaza with a clear line down the middle to separate its two halves, another has stairs divided in two by railings. This simple linear separation gets the message across easily with minimum verbal explanation. The only downside is that it makes no sense.

If every point in the city were either totally Besź or totally Ul Qoman, then there would only be a one-dimensional boundary between the two, and away from that strip each city would function like any other. More to the point, they could just put a wall up between the two and be done with it. It would be no more interesting than East and West Berlin. Establishing shots of a divided skyline reinforce this mundane idea.

The book's reality is much more subtle. Here, crosshatching means that much or all of the street or plaza are really in both cities at once. Which you're in isn't determined by your latitude and longitude, it's determined by human social construction. Rereading the book, I found it amazingly believable, and its believability a reminder of the power and flexibility of invisible social strictures.

I don't know if it's feasible to represent this in film. A blurring effect to represent unseeing of people and structures not in the current city could work well enough, but maybe it would be too confusing. And anyway it couldn't capture crucial subtleties -- the way unseeing is always somewhat fake and performative, even if you rarely admit it to yourself; the queasiness caused when you're not sure which city something is in.

The adaptation committed further bowdlerisation of the book's premise, not least the demotion of Breach from semi-mythological ultimate power to straightforward secret police no-one seems too worried about -- but turning crosshatching into a membrane is the worst.

In conclusion: if you saw (any of) the adaptation and were unimpressed, read the book. If the read the book, skip the adaptation, or at least be prepared to be disappointed by it. If you've experienced neither and read this article despite the spoiler warning, read the book even though you're a bit spoiled now, it shouldn't actually matter too much.