An epic sci-fi film based largely on the novel A Princess of Mars by Edgar Rice Burroughs. John Carter (played by Taylor Kitsch) is an American Civil War veteran who is miraculously transported to Mars, where he becomes known as Barsoom. He learns that the planet is dying from the loss of its atmosphere and water, and that only a peaceful alliance of its intelligent inhabitants can save the species of Barsoom from extinction. In the midst of his mission, Barsoom involuntarily becomes part of a conflict between the various nations of the planet, whose leaders include Tars Tarkas (Willem Dafoe) and Princess Dejah Thoris (Lynn Collins).