It's 1967, and 17-year-old Susanna Kaysen (Winona Ryder) is like a lot of teenagers: confused, insecure, struggling to make sense of the rapidly changing world around her. The psychiatrist she meets with (courtesy of her parents), however, gives this behavior a name, Borderline Personality Disorder, and whisks her away to Claymoore Hospital. Here, Susanna joins a shadow world of eccentric young women, among them charming sociopath Lisa (Angelina Jolie), pampered "Daddy's girl" Daisy (Brittany Murphy), and burn victim Polly (Elisabeth Moss). Guided by no-nonsense ward nurse Valerie (Whoopi Goldberg) and the hospital's head psychiatrist, Dr. Wick (Vanessa Redgrave), Susanna must choose between the worlds of those who belong on the inside of the institution and the often difficult world of reality on the outside.