Tart (2002)

Synopsis
Cat Storm (Dominique Swain) is a bored high school girl in New York City who follows her petulant, rich friends from one coming-of-age adventure to another. They experiment with cruelty, rudeness, brazenness, and idiocy before moving onto sex and drugs. Cat's best friend, Delilah (Bijou Phillips), is kicked out of school for using cocaine (her father's), forcing Cat to become best friends with Grace (Mischa Barton), who guides her into the arms of William (Brad Renfro), the boy Cat's had a crush on for some time. Eventually they all wind up at a luxurious country estate for a weekend of drugs, passion, and, inevitably, gruesome murder. ~ Buzz McClain, All Movie Guide