Originally, I watched this film to witness the brilliant acting of James McAvoy (because I've read so many praises of it, especially in this movie), but 10 minutes into the movie, I was no longer interested merely because of McAvoy, but also because of the plot. This movie is terrifying and intense and extremely nerve-wrecking, and although I am not a fan of thrillers, I really enjoyed it. The psychological background of the story is one I am familiar with in some way, since I have general knowledge about a number of disorders, including DID, but how it was portrayed makes me feel like I am learning about it for the first time. It provokes thought, especially with the line "those who are broken are the most evolved". That made me think for a moment. Wonderful film. A must see.