"Choosing not to believe in the Devil, won't protect you from him" - Father Lucas Trevant
It's about a young skeptic seminarist, that starts doubting his faith and then is sent to study exorcism in Rome.
Besides all the effects and the hollywood terror drama, the film is based on a real facts that helps to make the film even more interesting. It's full of symbology and some great short dialogues, things that comes back to your mind through the whole film.
By the way, no one could deliver it better than Antonhy Hopkins (Who interpretates a old exorcist), his acting is always captivating.