The England of Alfonso Cuaron’s “Children of Men” at first seems like a magnificently imaginative rendering of a nightmarish future—cold and sooty, veiled in mists, heavy with the ubiquitous menace of the police state—until you realize that Cuaron’s England already exists. Futuristic gadgets are visible here and there, but “Children of Men” has much in common with the low-budget, ready-made atmospherics of a good “Twilight Zone” episode. The careful placement of one or two key special effects works better than an onslaught of digital dazzle.

A cast of strong actors, led by Clive Owen and Michael Caine, anchors the story even more firmly to reality, gives it blood and guts. But although it depicts its dystopia as homegrown in ways similar to distant cousin “Twelve Monkeys”, Cuaron’s understatement allows more space for the anxiety to seep in rather than crowding its characters into a jittery futureshock house of horrors.

Indeed, what really impresses in “Children of Men” is how strikingly our present looks like Cuaron’s future. The end is nigh, but the apocalypse comes not with the blinding flash of a hydrogen bomb but a long, slow trip to species extinction, shepherded by shock troops and narrated by “Access Hollywood”. The vital tip on the fulcrum is not ahead of humanity but behind it, somewhere in the recent past when women ceased to be fertile (for reasons Cuaron and his writers wisely omit). Psychologically, it is a perfect evocation of what it’s like to live in the West now, a civilization numb with the affectless boredom of waiting for the end. “Children of Men” is therefore anything but a cautionary tale. The problem of infertility might be a judgment of God or an evolutionary correction, but in any case no ‘warning’ can be made about a future afflicted as if by a supernatural curse. The girl’s pregnancy allows for a ray of hope, but that too seems accidental, and there’s no guarantee that the modern Noahs who rescue her in their Ark can rescue humanity from itself.

Often the film is so grim it amounts to an essay on the role of administrative tedium in government-sponsored genocide. Life is harrowingly degraded, parcelled out into zones of suffering. A rich, sensual nausea awaits sensitive viewers. Here is a movie with a stench, as it were, a black fairy tale practically humid with animal squalor. “Freedom” consists of negotiating one choice: how to die. The rich get poison pills to take in the comfort of their living room (“Quietus”, with the ‘empowering’ tag line “You decide”, a joke to make Terry Southern proud) while the poor ride buses or stand in endless queues.

These details are far more affecting than the cat-and-mouse plot which, aside from a thrilling car chase shot with amazing intimacy by Emmanuel Lubezki, mostly hits conventional notes. Instead, Cuaron’s inspired touches are visible in the background: piles of cow corpses in a field, burned to stop a pandemic, or a dazed mother holding the severed arm of her daughter after a bomb levels a coffee shop. Together these believable details underline this frightening world’s proximity to ours. “Children of Men” is chilling because it isn't a warning, a prophecy, or a call to action. It’s a map of where we stand today; if we squint our eyes and look, the future is already upon us. Cuaron’s morbid masterpiece is the best film of 2006.