Years after he changed the landscape of filmmaking with The Exorcist, filmaker and writer William Friedkin moves from fiction to fact with this documentary. What began as a brief conversation between Friedkin and Father Gabrielle Amorth - the head Exorcist for the Diocese of Rome for over 30 years - as two professionals who knew of each other's work, soon transformed into an once-in-a-lifetime opportunity, as Amorth agreed Friedkin could film an exorcism ceremony. It would be the ninth exorcism for a painfully afflicted woman, and it would be filmed by Friedkin alone, with no other crew allowed, no light other than the natural light in the room and a small digital camera-and-mic unit that could capture the ritual and its revelations.
Combining the startling and singular footage from Cristina's exorcism with interviews from priests and psychologists, neurosurgeons and non-believers, Friedkin guides us on a journey into the twilight world between the boundaries of what we know and what we don't.