A field full of diamonds drives men to murder in this action-packed serial thriller starring screen legend Boris Karloff.

After being falsely accused and imprisoned in India for the death of a powerful Rajah, American adventurer Richard Grant escapes and flees to Africa. In the jungles of the Dark Continent, Grant meets pretty Muriel Armitage, who is searching for her missing brother, Tom. Upon discovering a rich diamond deposit in a volcanic cave, Tom was kidnapped by ruthless, big game hunter Harris and his evil Arab accomplice, Mustapha. Harris happens to be the one man who can clear Grant's murder conviction, so the fugitive decides to join forces with Muriel. Together they face carnivorous beasts of prey, marauding native tribes, and the deadliest peril of all -- murderous human greed.