It’s all too rare to stumble on to something genuinely original. And it’s even more unexpected for that film to be a vampire movie, a genre that has been explored and exploited in every conceivable shape and form. But Let the Right One In, a deliciously macabre story of a tentative romance between a bullied 12-year-old boy and the strange girl who moves in next door, is pure magic.

It’s safe to say that the film, set in the early Eighties in a sterile suburb of Stockholm, is unlike pretty much any other vampire film you might have seen before. The director Tomas Alfredson pays far more attention to the awkward friendship between these two outsider kids than he does to the film’s more gruesome elements.

At nearly two hours in length and paced with the meticulous deliberateness of a killer stalking his prey, the film certainly doesn’t share many structural similarities with a classic horror flick. Alfredson allows us the breathing space to appreciate the purity and beauty of a dusting of frost on a branch; he frames his violence in austere wide shots. It’s witty, too — Alfredson relishes the bizarre juxtaposition of the violence of a vampire’s existence with the drone of normal life in this snowbound concrete backwater.

The two young actors who carry the story are superbly cast. Kare Hedebrant, who plays the bullied loner Oskar, is an unearthly blond child who looks as though he has just hatched from an egg. His otherworldly weirdness makes him a magnet for the school bullies; their cruelty feeds a deep well of anger in Oskar that he releases in savage revenge fantasies.

Lina Leandersson is mesmerising as Eli — ragged and feral-looking, she manages to convey both a timeless resignation and a gauche naivety when it comes to the world that 12-year-olds in 1982 inhabit. A Rubik’s cube is a thing of wonder for her.

But for all its languorous pacing, its mordant humour and the unexpectedly sweet-natured approach to the bonds that grow between the two children, Let the Right One In is underscored by an unsettling violence. This is not the kind of vampire film that will have you chewing your nails with suspense, but the dreamlike drift of the narrative makes the blood-letting, when it comes, all the more disquieting. And the real horror comes at the end when you recognise Eli’s darker motives for befriending Oskar; that his future is potentially as cursed as hers.

15, 114mins

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