Addie Downs and Valerie Adler will be best friends forever. At least that's what nine-year-old Addie believes when Val moves into the house across the street. But in the wake of betrayal during their teenage years, Val is swept into the popular crowd, while mousy, sullen Addie becomes her school's scapegoat.

Fifteen years on, Val has found a measure of fame and fortune as the local weathergirl. Addie, meanwhile, lives alone in her parents' house, looking after her troubled brother and trying to meet Prince Charming on the internet. She's just returned from Bad Date No. 6, when she hears a knock at her door. There, on the step, is her long-gone best friend, blood on the sleeve of her coat. 'Something terrible has happened,' Val tells Addie. 'Can you help me?'