Continuing directly from Tarzan the Untamed, Tarzan follows the trail of Jane and her German abductor into the inaccessible land of Pal-ul-don. Jane must survive captivity and escape while Tarzan moves through rival cities and peoples in a primeval lost valley.
The novel continues the wartime consequences of Tarzan the Untamed, with German military involvement still shaping the search for Jane before the trail enters Pal-ul-don. From there the story becomes a full lost-world romance of rival peoples, strange creatures and survival, while the First World War remains the force that set the pursuit in motion.
