AllMovie

A machine able to extract gold from the ocean floor is desired by both Axis powers and the FBI in this 13 chapter Universal serial directed by the team of Ray Taylor and Lewis D. Collins. Milburn Stone -- later "Doc Adams" on television's Gunsmoke -- starred as G-Man Tom Brant, with blond Jan Wiley, as a girl reporter, and Dennis Moore, as an intrepid detective, all three stymied by the mysterious "Master Key," a villain who always seem one step ahead. Five screenwriters worked on the script. Future B-Western star Al "Lash" LaRue made his screen debut in this serial, billed as Alfred LaRue and playing one of the villain's henchmen.