Set in the suburbs of Rio de Janeiro, A Wolf at the Door opens with a mother arriving to pick up her young daughter at school, only to learn that the girl already left with another woman. A parent’s worst nightmare takes increasingly sinister turns as it delves into the events that led to the girl’s kidnapping, the story morphing into an intense psychological drama of lust, betrayal, and revenge told through flashbacks revealing a marriage on the verge of crumbling and a secret, erotic affair.