Tarzan, TARZAN AND THE LOST EMPIRE, (Tarzan Achives #13)

When Dr von Harben finds Tarzan in the jungle, he asks him to find his son, Erich, who was searching for The Lost Tribe of the Wiramwazi Mountains. Tarzan and his monkey friend, Nkima set off alone to find him. Along the way, he is captured by Bagego, a people who trade with the Lost Tribe annually, but are at war with them the rest of the time. They believe the Lost Tribe are the spirits of their dead, and that Tarzan is one of the Lost Tribe and should be killed.