Sadly, a lot of people may be driven away from the book due the movie -- which follows a very simple plot line.
But the book does not have a simple plot line. It is complex, twisting and its purpose only shows in the very last line. In that line, the whole story finally clicks; all plots and twists, all descriptions and names, everything clicks. And you stay there, suddenly hit by its plot like a brick hitting you in the side of your face.