Years after the shocking murders that made the name Charles Manson synonymous with pure evil, the three women who killed for him - Leslie Van Houten (Hannah Murray), Patricia Krenwinkel (Sosie Bacon), and Susan Atkins (Marianne Rendon) - remain under the spell of the infamous cult leader (Matt Smith). Confined to an isolated cellblock in a California penitentiary, the trio seems destined to live out the rest of their lives under the delusion that their crimes were part of a cosmic plan - until empathetic graduate student Karlene Faith (Merritt Wever) is enlisted to rehabilitate them. Convinced that the prisoners are not the inhuman monsters the world believes them to be, Faith begins the arduous process of breaking down the psychological barriers erected by Manson. But are the women ready to confront the horror of what they did? Boundary-pushing auteur Mary Harron (American Psycho, I Shot Andy Warhol) presents a provocative new perspective on one of the most notorious crimes of the twentieth century.