The female leader of an international crime ring steals a valuable artifact that can give her the power to control men's minds. Federal agents are dispatched to get it back and stop her evil plans.

The Daily Clarion hires detective story writer Steve Colt to investigate the deaths of a group of scientists working on an atomic rocket development project. Behind the killings is fortune teller Sombra, a spy from an Asian country intent on world domination, who is determined to pilfer the atomic rocket by luring workers from the project to her parlor and killing them with black widow spider venom when they refuse to cooperate.

Imprisoned during the Spanish Civil War, John "Kit" McKittrick is released when a New York City policeman pulls some strings. Upon returning to America, McKittrick hears that a friend has committed suicide, and he begins to smell a rat. During his investigation, McKittrick questions three beautiful women, one of whom has a tie to his refugee past. Pursued by Nazi operatives, McKittrick learns of the death of another friend, and begins to suspect the dark Dr. Skaas.