Frank Conklin

A mad scientist named Dr. Satan plots to steal key pieces of technology to enable him to build an army of robots based on his prototype to conquer America. The only one standing in his way is Bob Wayne, who fights Satan as the enigmatic Copperhead. Mysterious Doctor Satan is a 1940 film serial named after its chief villain. Doctor Satan's main opponent is the masked mystery man, "The Copperhead", whose secret identity is Bob Wayne, a man searching for justice and revenge on Satan for the death of his step-father. The serial charts the conflict between the two as Bob Wayne pursues Doctor Satan, while the latter completes his plans for world domination.

Justo antes de Navidad, la joven Lee Leander (Barbara Stanwyck) es arrestada por el robo de una joya y es procesada por el fiscal John Sargent (Fred McMurray) pero el juicio se pospone hasta después de Navidad. Sargent acaba sintiendo pena por ella y decide llevarsela con él a casa de su madre. Después de pasar unos dias juntos, ámbos se enamoran, pero les surge un nuevo problema, como solventar el asunto de la justicia.