Over the weekend I caught Children of Men, directed by Alfonso Cuarón (Y Tu Mamá También ). I liked that it took seriously the implications of its scenario (a world in which no baby has been born in 18 years) rather than treating it merely as a plot device used to get the hero up and perspiring (Minority Report, anyone?). With the world ending not with a band but a whimper, the London depicted has slipped into sullen malaise–although the dystopian vision of trash-choked streets, bleery pubs, and public transport running the gauntlet of newly minted Morlocks seems not overly divergent from the less salubrious parts of the real metropolis.There is, however, a wonderful scene that exemplifies one of the unique pleasures of speculative fiction–it can make us nostalgic for the present. In this case, Theo Faron (Clive Owen), on an errand to see his plutocratic cousin, is ushered through security gates at Admiralty Arch. Once through, a simulacrum of the deceased world, with guardsmen parading and bands playing, lingers in the sun-dappled “green zone.” (And one momentarily wonders if the film’s spectre of a childless world is actually a sly way of smuggling in a message about Britain’s upward-swooping Gini index).But this is also an action movie, and our hero does get the opportunity to act heroic. The last section of the movie is a virtuoso immersion in urban warfare, with the camera giving the sort of first-person POV that made me think of my all-too-brief experience with the XBox game, Gears of War. However, the moment that a hail of gunfire spatters the camera lens with arterial blood was simultaneously darkly exhilarating and oddly distancing. Rather than making us feel vulnerably present at such carnage, this cinema verité technique only reminds us how safe we are when we vicariously experience on-screen death.