Most movies derived from books differ. I would say 99.99999% of all movies that have their origins from novels deviate from the source material. I accept this. It is the way of the world. But Disney’s John Carter, ruined, destroyed and obliterated the beloved works of Edgar Rice Burroughs. I love the books and reread them as much as possible. Adventure and heroics, with pulp serialized speed and transition, suck you into the story and releases its magic onto you. The movie failed on all levels. There should have been the allure and pacing of Indiana Jones, and it should have captured us with the magic of the first Star Wars films. After decades of technology advancement and the imaginations of Disney and Pixar backing, this should have awed us like Star Wars did, but it fell flat. But most of all the story ruined it as a whole, ERB is most definitely rolling in his grave over the murder of his stories.