Sister Ann believes she is answering a calling to be the first female exorcist… but who, or what, called her? In response to a global rise in demonic possessions, Ann seeks out a place at an exorcism school reopened by the Catholic Church. Until now these schools have only trained priests in the Rite of Exorcism -- but a professor recognizes Sister Ann's gifts and agrees to train her. Thrust onto the spiritual frontline with fellow student Father Dante, Sister Ann finds herself in a battle for the soul of a young girl, who Sister Ann believes is possessed by the same demon that tormented her own mother years ago. Determined to root out the evil, Ann soon realizes that evil has been expecting her.