Suspiciously unambitious Cassie (Carey Mulligan) leads a quiet existence as a barista who lives in her parents’ house since dropping out of medical school. She and her friendly boss, Gail (Laverne Cox), gab away days at the cafe. The way she spends her evenings, however, reveals a boiling vendetta. Men who cross her path are in serious danger, as beautiful and brutal Cassie seeks to heal from past trauma by doling out scathing lessons. When Ryan (Bo Burnham), a former classmate, re-enters her life, so does the possibility of healing—until new details about the death of her best friend infuriate Cassie and inspire her most potent confrontation yet.