I didn´t know this was based on a book when I choose to watch this but the story had youth-novel printed all over it with two young protagonists. Unfortunately this is only the first part of a story that produced 4 novels in total. The movie wasn´t a success though generating below 20m$ while costing 55m$ which in Hollywood closes the door for sequels.Which is a shame I guess because of all the youth novel movie adaptations I saw this is one of the best with a story that not only relates to children. They didn´t overstress it in making it a 2.5 hour movie and the production in general is really good. But it works as a standalone movie with an open ending that leaves you with either your imagination or you take the route of reading the books.