|Anthony Hopkins||Father Lucas Trevant|
|Colin O'Donoghue||Michael Kovak|
|Ciarán Hinds||Father Xavier|
|Toby Jones||Father Matthew|
|Rutger Hauer||Istvan Kovak|
|Maria Grazia Cucinotta||Aunt Andria|
|Ben Cheetham||Young Michael|
Though he is filled with doubt about the subject, seminary student Michael Kovak finds he must attend a Vatican school of exorcism. Believing possession to be the work of a troubled mind rather than actual demons, hel urges his superiors to look for answers in psychiatry. Then Michael becomes the apprentice of Father Lucas, a veteran exorcist, and encounters a terrifying force that causes him to question everything he believes.