Thirteen-year-old Tracy Freeland (Evan Rachel Wood) is a straight-A student who writes poetry. At her Los Angeles middle school, she is teased about her "cabbage patch" clothes by more popular girls. Her divorced mother Melanie (Holly Hunter) is a recovering substance abuser and high school dropout who struggles as a hairdresser to earn enough to support Tracy and her older brother Mason, who is an avid surfer. She buys Tracy a few new clothing items from a discount vendor in a van. Thus clothed and much to her delight, Tracy is invited by Evie Zamora (Nikki Reed), the most popular girl, to go shopping in Hollywood. Although Evie gives her a disconnected telephone number, likely as a mean middle school joke or ploy, Tracy takes the bus to Hollywood anyway. She finds Evie and a friend, only to learn that to them, shopping means shoplifting. Undaunted, Tracy steals a woman's pocketbook and the teens go on a shopping spree, whereafter Tracy and Evie become fast friends. Evie moves into the Freeland house and the two girls go into a downward spiral of hard drugs, sex, lies, piercings and petty crime. Meanwhile Tracy is upset about and torn between her divorced parents, both of whom are struggling to earn enough money to live. Tracy shuns her old, faithful friends and at home, taunts Melanie's boyfriend, a former cocaine addict. Melanie sees hints of what is happening with the two girls but is unable to stop them, further thwarted by Evie's manipulative but likely truthful claims of childhood abuse. As Tracy steadily shuts Melanie out of her life, Tracy and Evie become very close, even talking to each other in their own "gobbledigook" language. However, after the early thrills, Tracy's newfound popularity does not make her happier. In one episode, underage Evie and Tracy try to seduce Luke, a lifeguard in his early twenties who is a friend of Mason. Drawn at first into their kisses, Luke throws them out of his house and soon after, puts the house up for rent and moves away. All along, Tracy has taken to cutting her arm as a way to cope with her stress. One night in Hollywood her brother Mason and a friend make comments about a cute girl who has her back to them. When she turns around and answers with a scathing remark, he is shocked to see this is his sister, with a belly ring. Back home, the two girls have become so numbed they even laughingly hit each other for kicks, drawing blood. At last, Melanie is able to take Evie back to live with her guardian Brooke, an aging model and aspiring actor who also works as a bartender. Tracy seems to agree with this step, after which Evie snubs and betrays her at school.
Failing seventh grade, former honour-roll student Tracy comes home to find Evie, her guardian Brooke and Melanie waiting for her. When the women confront Tracy about her drug use and stealing, Tracy angrily blames Evie. Brooke says Tracy was the bad influence and that they are moving to Ojai, to get away from her. Melanie stands up for her daughter, saying Tracy was "playing with Barbies" when she met Evie. Brooke than grabs Tracy and pulls her sleeve up to show Melanie the many cuts and long scars on her daugher's left arm. Melanie, taken aback and shaken by this sight, tells Brooke and Evie to leave. Both mother and daughter weep on the kitchen floor as Melanie kisses her daughter's heavily cut arm. Although Tracy pleadingly tells her mother to let go of her Melanie holds on tight and they wind up in Tracy's room where they carry on hugging and fall asleep. The movie ends the next morning as Tracy wakes up with a start and later spins alone on a merry-go-round in the park, screaming.
