[2] It is the first of seven films, loosely based on the 1960 Kommissar X #73 detective novel from the Pabel Moewig publishing house.

[3] American private investigator Joe Walker is on vacation in Europe when he is approached by a mysterious woman who is looking for a nuclear scientist named Bob Carroll.

Meanwhile NYPD Captain Tom Rowland is assisting the local police investigating the deaths of two businessmen in separate bombings.

Oberon's secretary Joan reveals herself as the woman who hired Walker, and that she is Carroll's sister.

As Rowland makes his way to the island, Walker seduces Oberon's doctor and they free the female guards.