Beatnik Jerry takes his girl Angie to the carnival. Angie wants to go see the gypsy fortuneteller, Jerry does not but relents. After hearing bad news from the fortuneteller, Jerry goes alone to see her sister, dancer Carmelita. He is invited backstage, where he is mesmerized into becoming a psychotic killer. When he tries to kill Angie, she and his best friend Harold realize something's wrong.