Though nominally a vampire movie with the requisite blood and gore, "Let Me In" is actually unclassifiable. You could call it a romance, a cautionary tale or a tragedy. Each way, you'd be correct.
Its protagonist is 12-year-old Owen (Kodi Smit-McPhee, of "The Road"), who is bright and sensitive. We also see him wearing a Halloween mask and taunting a mirror with a knife: "Are you a little girl?" It turns out Owen is merely wishing for revenge on a school bully (Dylan Minnette), but this first impression remains hard to shake.
Living in isolated Los Alamos, N.M., in 1983, Owen is what we'd now call "at risk," with no father and a mentally absent mother (her face is never clearly seen). No wonder he's so touched by even the smallest kindnesses from his new neighbor, Abby (Chloë Grace Moretz, of "Kick-Ass").
Abby, also 12 - "more or less" - arrives with a man who seems to be her father (Richard Jenkins, haunted and haunting). He certainly feeds her, mostly with plastic jugs of fresh human blood. Meantime, Owen and Abby develop the kind of wholly honest relationship that only children are capable of; together, the two young actors are heartbreaking.
Writer-director Matt Reeves re-creates the eerie mood and mustard-yellow lighting of the 2008 Swedish hit "Let the Right One In" (itself based on a novel), though he also hammers away some subtleties and opts for disappointingly cartoonish special effects. Nevertheless, "Let Me In" is one of the few horror films that will trouble you long after the credits roll.