On the eve of his wedding, John Clayton, Lord of Greystoke (better known as Tarzan), receives a message from the witch doctor Mugambe that his homeland is in danger. It turns out that a treasure hunter named Ravens is searching for the lost city of Opar, and is destroying the jungle and desecrating the villagers' burial grounds in the process. Only Tarzan can stop Ravens and set things right in the African jungle, but will Jane stand for her fiance being away for so long?