Notably, Richard Kiel would eventually graduate from cheap Bond knockoffs to actual Bond films; he appeared as a villain in The Spy Who Loved Me and Moonraker.
Secret agents Dick Dagger (Mantee) and Harper Davis (Moore) are hunting escaped Nazi war criminal Rudolph Koffman (Murray), a wisecracking former SS colonel who has created a brainwashing machine. His first test subject is Erika (O'Neill), a beauty spa employee.
Dagger and Davis stumble upon the mind control plot while investigating the spa, which is run by Koffman's girlfriend Ingrid (Sue Ane Langdon). Dagger rescues Erika, and narrowly avoid death when Koffman orders her to kill the secret agent. Hoffman captures Davis and arranges a prisoner swap with Dagger. Unbeknownst to Dagger, Davis has also been brainwashed and tries to kill him on the ride home.Dagger manages to track down Koffman's secret lair, but is captured. Hoffman puts Dagger into the brainwashing chamber, but Dagger uses his secret agent gadgets to escape, smashing the machine in the process. In the usual secret agent fashion, he wipes out the guards, rescues Erika, and defeats Koffman in a one-on-one battle, saving the day.