Let the Right One In / Let the Right One In sounds like the title for the sequel to He’s Just Not That Into You or the new single from Carly Simon, but the actual product can’t be farther from pop trash. This Swedish film directed by Tomas Alfredson and adapted by John Ajvide Lindqvist from his own novel is a full-blooded vampire indie with (pardon the pun) bite.

Oskar is a 12-year-old boy ignored by mommy and daddy and picked on by the other kids at school. He’s essentially Pearl Jam’s “Jeremy” come to life but instead of going postal on his classmates, he spends his nights in the freezing snow stabbing trees. One night he is joined by his new neighbor, a young girl of the same age named Eli. She doesn’t seem to feel the cold and she smells funky. She promptly informs him, “Just so you know, I can’t be your friend.” But they bond over a Rubik’s Cube and Oskar slowly discovers that he has a secret weapon to get him through adolescent growing pains that poor Jeremy never had: a vampire.

Everything is executed with a straight face and the tone treads the line between a sweet, innocence-tinged “romance” between two children on the edge of teen-age angst and a creepy tale of genuine horror with an un-exploitative amount of gore. Nothing is held back and the results are enough to make Robert Pattinson and the rest of the Twilight cast run from the sunlight to the sanctuary of a hair salon. The young vampire’s killings are brutal and animal-like. The man who cares for Eli makes a sacrifice for her that would make Harvey “Two-Face” Dent ask, “Does that hurt?” We find out what happens when a vampire enters a room she is not invited into—hence the movie’s title. And in a scene that is both disturbing and funny in its youthful innocence, Oskar accidentally learns what Eli meant when she told him she’s not a girl.

Some parts of this film are seriously ridiculous: a sequence where we learn that housecats hate vampires is nearly slapstick and the climax at a swimming pool has the unintentional comic timing of a skit from The Muppet Show. Still, the misfires aren’t enough to dilute the potency of Oskar and Eli’s relationship. The sense of mystery the film creates for its world is absorbing. Unlike Anne Rice or Stephanie Meyer, we get zero backstory or mythology; we’re left to ourselves to draw conclusions. How did Eli become what she is? How old is she? Who exactly is her “guardian”? The process of filling in those blanks becomes part of the spellbinding fascination. Some of the things left unsaid do make for plot holes though, mainly, how does she manage to avoid getting caught after all that biting?

But Let the Right One In is so assured of its story that the two young performers drive us toward a satisfying, inevitable conclusion both characters deserve. An American remake is on the way, and with our luck, it’ll star Dakota Fanning and one of the Jonas Brothers. And it will certainly be a travesty to one of 2008’s finest films.

Let the Right One In opens in Hawaii on Fri., 2/27.