I think you'd have to watch closely in order to fully understand this movie, and perhaps if you watch closely enough you'll be able to suss out the ending, I; however, was not observant enough and so it came as a very big shock to me at the end. I won't spoil it by telling you what the suprise is, but I'll tell you this: The answer is right in front of you. It is so obvious, and if you don't figure it out before the end, you'll probably kick yourself! What annoyed me was that I felt torn between Pearce and Frank, because both seemed to be deeply in love with Elise, and vice versa. Oh, the choices. Thankfully, this was all sorted out at the end and I was fairly happy with the result.
Now thinking about it, I'm not entirely sure what the point of this movie is. It goes on a very long a drawn out route to find out who Pearce is and perhaps that is why it received such bad reviews. There isn't a lot of substance to it, but for some reason, I still enjoyed it. I realise this is a very confusing review, but I'm very on the fence about this movie. As I sit here I'm wondering whether the shocking finale is worth sitting the through the rest of the movie for and I think I'm going to have to say: yes. It's a unique movie, I don't think there have been any movies like this before and it is fairly entertaining. I am going to recommend this to you, because I want to see your reactions to the ending and whether or not you saw it coming, because that really is the climax of the movie and all there is to it.