Gimme Shelter demonstrates that Vanessa Hudgens should be considered the valedictorian of her High School Musical class. Hudgens convincingly chops nine years -- nine! -- off her age to play pregnant foster teen Agnes, aka Apple. Writer-director Ronald Krauss keeps his camera in Hudgens's face like he's looking for a fight, but she's still unrecognizable: hair hacked, face pocked with piercings, body thickened with an extra 15 pounds, and a feral anger in her eyes like a dog that's been beaten since birth. Apple's hard to like and harder to trust, but Hudgens makes us feel the desperation of having zero impulse control. And give Krauss credit for saying the word "abortion," something Judd Apatow didn't dare in Knocked Up. But when Apple and her fetus flee a clinic, he can't possibly ask us to agree that Hudgens's violent dumpster-diver would make a fit parent. But he does. And here's where we're asked drop the politics to see Gimme Shelter as the story of one girl and not a prescription for a nation. Or really, the story of the real-life woman behind the girl: Kathy DiFiore, a former abused wife and homeless mom who turned her house into a shelter for pregnant teens. DiFiore, played with empathy and steel by Anne Dowd (Compliance), is the hero of Gimme Shelter; and Hudgens's Apple is just the star. But though the arc of the film is saccharine as a Precious Moments figurine, Hudgens is too honest to believe in simple, happy endings. Squint closer at this broken doll and she's still furtively flipping the world the finger.