Everything about David Slade's "Hard Candy" is designed to unsettle its watcher: the voyeuristic camera getting up close in the faces of the actors; the chirpy innocence of a 14-year-old who looks and sounds much younger; the blood-red wall in the apartment of the grown man who has brought the teen to his home; the creepy flirting between the two of them. Her voice is vulnerable and squeaky; she knows she's in over her head. His voice is elaborately casual; he knows he's getting away with something. Or, rather, he thinks he is.

"Hard Candy," dancing on the borders of exploitation, knows that it's hard to watch. At times the filmmaking is like a kid waving something nasty in your face, taking pleasure in your discomfort. But it's also that rarity: a film that gives you something to think about, raising questions that linger long after the theater lights have brightened.

About 30 minutes into Brian Nelson's screenplay, things take an unexpected turn, and the plot is flipped over. Predator becomes prey, and the once-familiar narrative arc goes somewhere else entirely. You may not enjoy watching it, but you can't look away.

It's a startling introduction to a performer sure to be around for a long time. Ellen Page, who plays young Hayley, looks like a little boy; her hair is cropped and her frame is as tiny as her voice. (In real life, Page is in her late teens.) Her transformation in the film is uncanny: This hesitant, giggly girl, a Red Riding Hood in her scarlet hoodie, is suddenly a warrior woman, as tough as any superhero and 10 times as cold. "Jeff," she says to the wolf, in a voice of steel, "playtime is over."

Played by Patrick Wilson, whose chilly handsomeness perfectly suits the role, Jeff is something of a cipher. (For that matter, so is Hayley; it's just that Page's performance is showier.) You know he's a bad guy, from the first moments — what other kind of adult would lure a 14-year-old to his home and serve her alcohol? But while the character doesn't earn our sympathy (how can he?), as he squirms helplessly, we squirm a bit watching him as well.

This nightmare tale of girl power is at times implausible but never unbelievable, thanks to the honesty of the actors. It's also at times nearly unbearable, due to its occasionally gruesome details (we hear a razor doing its work) and tight focus. This is a two-character film (Sandra Oh appears only briefly as a neighbor), with two characters who both seem beyond redemption. But something about Hayley and her anger resonates, with a roar rarely heard in the movies.

In a voice entirely free of the nervous wavers we heard early in the film, she says near the end, "I am every little girl."

Moira Macdonald: 206-464-2725 or mmacdonald@seattletimes.com