British engineer Vance Pierson invents a new generator in the shape of a Ferris wheel and moves his family to Spain to supervise its construction. Looking for a house, he meets Laura Blanco and stops her from setting fire to her house in an effort to collect the insurance. He moves into Laura's house with his family but is drawn into a passionate affair with Laura that so jeopardizes his family life and his career that he ends the affair. Maddened by the rejection, Laura sets fire to the house, and Vance's wife and daughter burn to death. He is horribly disfigured trying to save them and vows revenge. He escapes from the hospital, perfects a presentable disguise, and sets out to find and kill Laura and her daughter. He sets fires that kill Laura's mother, brother, and sister-in-law, and Laura flees to a small coastal town and goes into seclusion. Vance travels with a carnival, and the owner's daughter, Liz, falls in love with him. Finding Laura, Vance starts a fire that burns her to death. He then takes her child back to the carnival, intending to throw her from the Ferris wheel, but the police and Liz convince him the child should be spared. After placing the child safely in the gondola seat, Vance leaps to his death, losing his mask as he falls.