Tarzan and the Golden Lion - Burroughs, Edgar Rice

Tarzan betrayed! He finds himself drugged and helpless, delivered into the hands of the Evil priests of Opar. Because of her love for Tarzan, La, High Priestess of the Flaming God, once again saves him. But she has been betrayed and threatened as well. To save her, Tarzan must flee with her into the legendary Valley of Diamonds.