Dr. Meredith has been driven from civilization by the criminal activities of his twin brother Bradley. With his infant daughter, he settles in the African jungle. But the Masamba tribes possess vast diamond mines coveted by crooks.

Dr. John Meredith has been driven from civilization by the criminal activities of his twin brother Bradley Meredith. With his infant daughter, he settles in the African jungle, where his ability to cure the native ills has resulted in his virtual control of the Masamba tribes, who possess vast diamond mines coveted by a gang of crooks. They use Shamba, a witch doctor jealous of Dr. Meredith's influence over the tribe, to further their schemes. They lure Dr. Meredith away from the jungle, and he is murdered by "Slick" Latimer. The natives believe that a sacred amulet is the secret of Dr. Meredith's power, and Shamba attempts to kill Nyoka, Meredith's now-grown-up daughter, to obtain the amulet (which actually contains the secret to the entrance of the Caves of Nakros). Jack Stanton rescues her and assists her in her efforts to recover the amulet. Latimer works with Shamba, and with Bradley Meredith, who poses as his murdered-brother so successfully that even Nyoka does not realize the deception.—ERBzine

Embarrassed by the villainous ways of his criminal twin brother, Bradley, the esteemed professor, Dr John Meredith, renounces the luxuries of the modern world to settle in the heart of the tangled African jungle. There, accompanied by his daughter, Nyoka, Dr Meredith dedicates his life to science, treating the indigenous Masamba tribe, only to spark furious animosity. With Shamba, the local, green-with-envy witch-doctor, bent on revenge, and Bradley's murderous henchmen determined to find a virgin diamond mine, the professor and Nyoka find themselves placed in harm's way. Now, blood stains the hands of the unscrupulous invaders. Will the precious diamonds remain in possession of the Masamba? Above all, will the dangerous criminals get what is coming to them?—Nick Riganas