IN most modern horror movies, which - for fairly obvious reasons to do with gaining the sympathy of the audience - generally concern the slaying of obnoxious and terminally stupid American teenagers gathered together in an Old Dark House, you can always tell who's going to be the first to go: it's the ones who have been sleeping together. Sure as guns are iron, there's a highly significant statistical association between non-membership of the True Love Waits Society and a propensity to explore the basement on one's own.

Which is one of the things that makes The Wicker Man, the cult 1973 horror movie celebrated in Ex-S (BBC1, 10.05pm) so strangely different from almost any horror film ever made. Although Eros and Thanatos have been going steady in fantasy fiction since Bram Stoker's Dracula and long before, and all the more passionately since Aids came along to replenish the genre's stock of metaphors, it's precisely the refusal of sex that makes death inevitable here.

To go too deeply into detail would spoil the film for anyone who hasn't seen it yet, but The Wicker Man is saturated with the imagery and mind-set of paganism, with all the earth-worship, fertility fetishism, and agricultural necromancy that that implies. When the crops fail on a remote Scottish island, the gruesome natives don't just settle back and rely on social security and the Crofting Commission like sensible folks. A human sacrifice is called for - and we know what kind of people make the best human sacrifices, don't we?

Almost as interesting as the themes of the film itself - the cruelty of paganism; the impotence of state authority in a small, remote community; the survival of magical, anti-rationalist thinking in the midst of civilisation - is the story of its making, distribution, and subsequent history.

Director Robin Hardy and stars Edward Woodward and Christopher Lee, revisiting the Scottish locations where it was filmed, explain how the film was almost shelved as (a) repulsive and (b) uncommercial by the production company's new owners, sent out for a brief cinema release as a B-feature (to another extremely scary picture, Don't Look Now), and then was almost universally forgotten until it began to pick up a certain cultish mystique in the late 1980s - not to mention a reputation as a piece of high 1970s British camp, largely on account of Britt Ekland's nude, wall-slapping ritual courtship dance. Carry On isn't in it.

Now, as demonstrated by the enthusiastic remarks of a group of New Age twentysomethings with Celtic tattoos (that's Celtic with a hard C, folks) and faces full of ironmongery, The Wicker Man has become keenly appreciated not only by mainstream film buffs and horror hounds but by people who find in it a vindication of their own mystical beliefs. It's as though a movie of The Diary of Anne Frank were to become a hit with Nazis, who'd come along to cheer the feelgood ending when the stormtroopers haul the Frank family out of the attic. It's a strange film all round.