I was very skeptical in seeing this movie, because in the last years all of the horror movies (except for few titles, and believe me, I devoured the horror genre since I started watching movies) were extremely disappointing, with a very generic scenario and lots of cliches, not to mention poor dialogues, lots of plot holes and so on.
But today I decided to give this movie a chance, because the main idea of how the victims are "exorcised" got me intrigued. It was a pleasant surprise to not see the ordinary Bible, Holy water and prayers involved in an exorcism, but something that's rather scientific and psychological. The action is very intense, not because of jumpscares and loud soundtrack, but because of that intense psychological battle between Dr. Ember and the victims.At some point the scenario is even puzzling you as an audience, because you cannot tell which of the characters are in the real world and which ones are living the illusion within the possession.
As I don't want to give much spoilers about the movie, I can tell you that it is worth your time. It is not the mother of horror movies, but it brings a new idea for the whole possession concept.