A warrior may change his metal, but not his heart.

From a cave in Arizona, former confederate soldier John Carter mysteriously transports to the surface of Mars. After a few successful trials with the local Martian population called Tharks, a nomadic green-skinned race with six limbs, he finds himself as a new, and respected, member of the tribe. Soon after, the Tharks capture a humanoid red-Martian named Dejah Thoris, who is a princess among her people. It is then that John Carter must choose to either ignore the captured princess or take action.

The first book of the Barsoom series, A Princess of Mars was published first as a serialization in 1912 and then as a novel in 1917.