Thinking about going to bed, this film started late on Film 4. Thought I'd watch the beginning out of curiosity as I have never seen Gerard Butler in a bad film to date. However, once it started, I could not leave the film; it was really gripping. I agree, this film is not for anyone who is adverse to extreme violence, but taken in its entirety, the violence is in keeping with the story and the mindset of the character that Gerard Butler plays. Jamie Foxx and Colm Meaney are also extremely good and the interaction of characters in the story is well done. This is a clever film that is gripping, psychological, thrilling, full of unexpected twists and keeps you not only on the edge of your seat, but guessing right to the end; an ending, which is unexpected! I am not going to go over the story, that is apparent in the film's write-up, but I will say this, if you enjoy a really good psychological thriller and can accept violence in its context of the story, then for 109 minutes you will be immersed in a film that does not let you leave it!