Ok, coming from a person who's read the book and watched the movie multiple times, both are really different from each other. The movie left out multiple things within the book like Ethan and Lena being able to talk to each other mentally, Marian, and some other things. The movie is really good itself. The actors played their characters really well, but this movie could have and should have been more. I swear if I become a director when I get older, I'm remaking this movie because it has so much more potential than it gave.