This was easily one of the better exorcism movies in a long time. And I feel like there have been way too many of them in the last couple of years. This one was different simply because it had a whole separate slowly evolving storyline that led up to the exorcism. And it was creepy as hell the whole time. It also had great casting. Eric Bana was great. Joel McHale was awesome as his partner. All the characters played really well off of each other and the story developed at exactly the right pace and didn't fall into that textbook, wash-rinse-repeat story. The tension was clearly there throughout the movie and there were numerous points where the audience will jump out of their chairs.
I very much recommend people checking this movie out. It was a huge surprise how much I really enjoyed this movie and I don't understand how underadvertised it was.
