It's easy to understand the tween- and teen-centric fascination with "Twilight," Stephenie Meyer's best-selling novel about the romance between a high school girl and a vampire. At least it is judging by the movie based on the book.

The love between 17-year-old Bella Swan (Kristen Stewart) and her strangely pale lab partner, Edward Cullen (Robert Pattinson), is as chaste as the relationship between any adolescent girl and, say, her Joe Jonas poster. Edward is a consummate gentleman on the outside, a seething cauldron of desire on the inside. And yet he remains tantalizingly just out of reach.

That's because Edward, as part of a coven of self-proclaimed "vegetarian" vampires, refuses to drink human blood. Edward knows that if things were to get too hot with Bella, it might end badly for her.

Lust is the elephant in the room here, and it's what gives "Twilight" its decidedly grown-up bite. That and director Catherine Hardwicke's wry humor.

Of course, like any self-respecting vampire movie, "Twilight" is also pretty scary. A roving band of out-of-town vampires who don't observe the Cullens' dietary restrictions shows up. One of them, James (Cam Gigandet), becomes obsessed with Bella, leading to the film's climactic showdown in a darkened, mirror-lined ballet studio. Good stuff.

The movie's not perfect. "Twilight's" special effects are something of a disappointment. The Cullen family's impossibly white skin looks less like pallor than face paint. I never quite bought Edward's running, jumping and tree-climbing ability either. Hardwicke relies too much on motion blur, which looks oddly dated, given the special-effects capabilities evident in, say, the "Spider-Man" movies.

But these are minor complaints. "Twilight" works as both love story and vampire story, thanks mainly to the performances of its principals. Pattinson and Stewart want to convince you that their characters are an undead freak and the girl who, against all logic, loves him. Yet they do it not by selling you on what makes Edward and Bella so different, but by finding their flesh-and-blood humanity.

--Michael O'Sullivan (Nov. 20, 2008)

Contains violence and a scene of sensuality.