Ireland 1963. The 17-year-old orphan girl Anne Marie becomes pregnant, raped by her cousin. She is housed in a monastery by her aunt and the pastor. She finds other young women in the Magdalena home, who have broken the strict rules of Catholic Ireland in a similar way. Immediately after her arrival, her identity is changed and her name is Theresa. Each woman suffers unspeakable cruelty and violence from the Mother Superior, despite her gentle-faced appearance and outwardly soft-spoken demeanor.