A man walks into a coffee shop, pushing through a rapt crowd to reach the counter. He barely seems to register the news on the screen playing in the corner: that “Baby” Diego Ricardo, the youngest man in the world, has been killed in a fight after he refused to sign an autograph. He was eighteen years, four months, twenty days, sixteen hours, and eight minutes old. We follow the man out onto the street. It’s recognisably central London—there’s even a WH Smith’s in the background—but obviously not now. Animated posters are splashed across the walls of the buildings and buses. The cars have a hunched-over, solid cast to them. There’s a strong police presence. Bags of rubbish piled up at the roadside. And as the man stops to add something, perhaps sugar, to his coffee, the cafe he just walked out of explodes, filling the street with shrapnel and black smoke.

It’s not quite the cinematic equivalent of a door dilating, but it’s not far off. Alfonso Cuaron’s adaptation of PD James’ 1993 novel Children of Men (which I haven’t read) does a remarkably good job of showing its world rather than telling about it. The above explosion, for instance, is just something that happens: an everyday occurrence. Once you accept the story’s premise, that humanity became globally and near-instantly infertile a little over eighteen years previously, the grim, grimy world it presents hangs together. You can kick it, as you can kick the worlds of films like Gattaca and Code 46. With no children, all sense of stewardship over the planet has vanished, and a terrifying fatalism hangs in the air. Things are falling apart: a tv program flashes up tragedies and atrocities from around the world, before asserting that Only Britain Soldiers On (or words to that effect). It has done so, it seems, by retreating behind its borders, and pursuing a ferocious policy of evicting any and all immigrants, or at least rounding them up to be held in internment camps, such as the one at Bexhill-on-Sea.

There seems to have been a small surge of interest in British dystopias this year. Aside from Children of Men, we’ve had the big-screen adaptation of V for Vendetta, Jo Walton’s latest novel, Farthing, and Jim Younger’s debut, High John the Conqueror; and this year’s Sidewise Award-winning novel was Ian R. Macleod’s wonderful The Summer Isles. You can make of this what you want: on the one hand, the original stories were written over a span of more than twenty years, so in many ways it’s an entirely artefactual surge, but on the other, it’s undeniable that many of the issues they address—of liberty, privacy, and complicity—have a depressing contemporary relevance.

Of the two films, Children of Men is the better by far: more detailed and more human. By the standards of action films—arguably by the standards of film in general—it is admirably down-to-earth, both in its set pieces (there’s a marvellous, tense escape scene, using a car so old that the characters have to get out and push it so that it can be jump-started) and in its depiction of what human bodies can take, and what they look like when they’re damaged. The man in the coffee shop, Theo (Clive Owen, in a superb performance), is well on his way to middle age, and spends half the time limping around in a tatty 2012 Olympics top and flip-flops. People die matter-of-factly, messily, and without warning. Nothing is soft-pedalled. The film’s flat, grey palette, and use of long one-take tracking shots on hand-held cameras reinforce the sense of reality: one astonishing sequence late in the film, in which Theo has to get into a battered building besieged by the army, and then out again, lasts for about six minutes, consists of about three shots, and is as harrowing as any war footage broadcast on the news.

The object of his search is the film’s other main character, Kee (Claire-Hope Ashitey), a refugee who is, miraculously, pregnant. As you might expect, given conditions in the UK, the plot revolves around Theo’s attempts to get Kee out of the country, via an offshore rendezvous with a boat from the (possibly apocryphal) Human Project, perhaps the one group who are still looking for ways to reverse the plague of infertility. It is very much to the film’s credit that it doesn’t play up the symbolism inherent in this scenario too heavily. There’s Kee’s name, of course, and when Theo meets her she’s under the guardianship of a resistance movement called the Fishes, and when he finds out she’s pregnant, the revelation takes place in a barn; but that’s more-or-less it. Kee is more than a macguffin, and though she doesn’t know who the father is, it’s not a miracle birth. And when she and her baby are seen in public late on, people react with the diversity of reactions you would expect: some reaching out to touch her, some crossing themselves, some not sure what to do.

When I walked out of the cinema, I said to my friends that I wasn’t sure whether Children of Men was genuinely excellent, or simply the best-directed bad sf movie I’ve ever seen. I said the world hangs together if you accept its premises, and that’s true, but you do have to accept those premises—the sudden and human-specific infertility, for which no explanation is given, and the presence of vast numbers of illegal immigrants even after a decade or more of closed borders. It’s a setup that verges on the melodramatic, and there’s something about the timescales involved, to my mind, that doesn’t quite track. Fortunately, we want to handwave things. There’s so much else to admire about the film, technically and artistically, that it fully earns both our suspension of disbelief, and the few redemptive moments it allows itself. Perhaps the most telling aspect of the film is that there is no grand uprising, no dramatic change in the status quo; indeed, we barely get to see the people in charge. The closest we get is a visit to a privileged relative of Theo’s. The rest of the time we are, like the characters, left to struggle with the pieces of a broken world.

EDIT: some more discussion here (including about how feminist or not the film is) and here (including about how ambiguous or not the ending is).