Tarzan and La pass through a secret route into the legendary Valley of Diamonds, where they encounter a strange society dominated by intelligent gorillas, and with Jad-bal-ja’s help Tarzan survives the valley and eventually helps La regain her position in Opar. Meanwhile, Flora’s companions and Esteban turn against one another over the stolen gold, and the real Tarzan is drawn into a final struggle with his impostor when Esteban also attempts to seize the diamonds Tarzan has acquired. Jad-bal-ja relentlessly pursues Esteban, and although Tarzan ultimately loses the diamonds he recovers the Oparian gold, while the false Tarzan ends his adventure as a captive of another tribe, paying the price for his deception and greed.
