First of all, if you can read something, better do that and only then watch the movie. To see if your imagination and fantasy after reading something is near/far from something that the director had in his mind.

The book itself is solid, interesting read, I love thrillers and mysteries and as a thriller there are multiple options to make you think that you know the answer. To some it might be predictable, to some like me, are let to be driven by the book. It is a long book and has some parts that could have been shorter ... but at the finish you feel good about it.

The movie however, I know it is difficult to put everything in a two hour movie, plus to keep the focus and the things interesting, but the scenario is changed. There are so many good book adaptations on screen, but sadly this is not one of them. So many things are not like they are shown in the movie. That is what bothered me the most. Stick to the story! And secondly I was not impressed with the acting at all. Very frigid, yes I know the book is a little bit dark and the characters are as well, but somehow even the slightest emotions are presented very cold and robotic.

You don't have to agree, after all that is my opinion. And to conclude my opinion, I say read the book. Much more fun.