Anthropologist Dr. Brockton unearths a primitive troglodyte -- an Ice Age "missing link": half-caveman, half-ape -- in a local cave. Through medical experimentation, she manages to communicate with him and domesticate him before he's let loose by an irate land developer and goes on a rampage, terrorizing the local citizenry.

U.S. Secret Service agent Peter Novak goes undercover with Scotland Yard officer Thompson to halt a murderous gang of counterfeiters known as the Golden Goose. Although Peter is unsure about John's loyalties, the two infiltrate the gang and win the trust of thug Nick "The Owl" Harrison before enduring a series of double-crosses.