Thuvia, Maid of Mars is a science fantasy novel by Edgar Rice Burroughs, the fourth of the Barsoom series. The principal characters are Carthoris (the son of John Carter of Mars) and Thuvia of Ptarth, each of whom appeared in the previous two novels. While typical in many ways of Burrough's Barsoom novels, it also includes some inventive elements. Carthoris is madly in love with Thuvia. This love was foreshadowed at the end of the previous novel....