B>First Published - 1913-1914. Matai Shang secretly frees Dejah Thoris, Thuvia, and Phaidor from their prison but does so for his own purposes. John Carter pursues Matai Shang and Thurid, a rebel Dator (prince) of the First Born, across Barsoom, eventually finding himself in Okar, the northern polar nation of the Yellow men. There he discovers that a powerful magnet has destroyed every fleet and ship which has attempted to explore the north, and kept the Okarians' secret refuge safe for countless ages. Carter also finds his father-in-law, Mors Kajak, a prisoner. With the aid of Thuvan Dihn, Thuvia's father, as well as Talu (a rebel prince of Okar), they overthrow the last vestiges of Thern power and rescue Dejah Thoris. But they call upon the nations which have befriended Carter through the years, who send a vast armada northward to rescue him. Carter thus has to destroy the great magnet as well as Matai Shang's plans. The Jeddaks of Barsoom's greatest nations proclaim John Carter Warlord of Mars.