"The Master Mind of Mars" is a science fiction novel by Edgar Rice Burroughs, the sixth book in his Barsoom series. It follows Ulysses Paxton, a mortally wounded American soldier who wills himself to Mars while reading a John Carter novel. There he becomes apprentice to Ras Thavas, a brilliant but amoral surgeon who has perfected brain transplantation. Paxton falls in love with Valla Dia, a young woman whose brain Thavas has placed in the aged body of a princess. Driven by love, Paxton embarks on a perilous quest across Barsoom to restore her to her rightful body.
