UNCLE, an organization to combat international crime, learns that WASP, an international crime syndicate, plans to take over Western Natumba, a newly-independent African state, by killing its President Ashumen when he and two of his ministers visit the Vulcan Chemicals plant in the United States. UNCLE's secret agent Napoleon Solo is assigned to prevent the assassination. He enlists the aid of Elaine May Donaldson, a housewife who was Vulcan Chemicals owner Andrew Vulcan's college sweetheart. Vulcan becomes attracted to Elaine once again when Solo has her pose as a wealthy and glamorous widow. She and Solo gain admittance to the Vulcan plant, and there they discover that Vulcan and Ashumen head WASP. Alfred Ghist, an evil scientist employed by Vulcan, captures Solo and Elaine and hangs them by their wrists in a room filling up with scalding steam. In the room directly above, an explosion is set to kill Ashumen's two ministers, who are innocent of any involvement in WASP. Solo and Elaine escape, saving the two Africans; and instead, Ashumen and Vulcan are killed in the explosion.
