Tarzan rescues elderly scientist Dr. Brooks. The man is held by the followers of Zar, God of the Emerald Fingers. His daughter Mary has also been searching for him. Tarzan searches for Mary. Everyone is captured by the people of Zar. They are brought before Eltar, the high priest. Two evil safari guides are killed. The others are freed, but they must never return. Mary and her father decide to stay with Tarzan.