This flawed sequel uses footage that was cut from its precursor, King Solomon's Mines, along with repeats of a few scenes from that film, to construct a story about a return to Africa to look for the fabled mines. Harry Quartermain (George Montgomery) is the son of the man who first set out on the quest for the source of Solomon's wealth, and he is determined to succeed where his father failed. He goes to Africa with his good friend Rick Cobb (David Farrar) and as they continue on their journey, Erica Neuler (Taina Elg) joins them. She is the daughter of a missionary who has been killed by a local tribe. As the trio fight off deadly snakes, crocodiles, and similar denizens of the jungle, Harry cannot hide his antagonism toward Erica. She is German, and Harry's mother was killed at sea by Germans in World War I. Only the determination to find the mines and a certain ambivalence in Harry's feelings toward Erica, and vice-versa, keep the trio united in their goal.