"Thuvia, Maid of Mars" by Edgar Rice Burroughs is a science fantasy novel published in 1916. The fourth book in the Barsoom series shifts focus to Carthoris, son of John Carter, who loves Princess Thuvia of Ptarth—a woman promised to another. When Thuvia is kidnapped and Carthoris is framed, war threatens to erupt between Martian nations. His desperate rescue mission leads him to ancient Lothar, where a mysterious race creates deadly illusions from pure thought.