Rebels on the red planet! An Earthman Harry Thorn exchanges personalities with an ancient Martian and pursues a vicious criminal (another Earthman who had been sent earlier) who seeks to destroy Martian civilization. There's also a race of yellow aliens apart from the hot-looking humanoids, and these guys have a death-ray which becomes important to the conflict. Follow Thorne's amazing adventures on this distant world as he attempts to fulfill his obligations. „The Swordsman of Mars" novel is one of the five planetary romances written by Kline in the 1930s. Considered by many to be the only true equal of Edgar Rice Burroughs, Otis Adelbert Kline was a master of the sword and planet genre. His adventure novels became science-fiction classics.