When you start watching this movie, the plot is obvious: a nobel-nominated professor heads off to Sweden to get his award and his son is kidnapped. The ransom is paid, the son is returned. All is well in the world. Its at this stage you realize the movie hasn't finished and you then enter the next phase. The plot twists around, and you get to learn more about the kidnapper, why he did it (hint: revenge!). Then, just as you get your head around this new plot, it twists again, and heads off in a different (and darker) direction. Throughout the movie, just when you think you understand the characters and their motives, things change around and you have to reevaluate your position (and pay attention to things). The only criticism is that the first part of the movie seems to develop very slowly, whilst the second and third parts move quickly; a bit of judicious editing in that first part would have been welcome.