Frankie and Patch are friends who take a small-time carnival from town to town, often bribing local authorities to let them stay.
Among their ruses to fleece the rubes is a dunk tank, in which Frankie perches, made up as a clown, and mercilessly heckles the customers. He is a public face of the carny, whereas Patch sticks to running the business behind the scenes.
Into their life comes Donna, a wayward 18-year-old who is bored with her life at home. Donna strikes up a friendship with Frankie and follows the carny on the circuit. She eventually joins the troupe, learning how to con customers and also doing an exotic dance that is more suggestive than lewd.
The dark and brooding Patch persuades others that Donna is capable of much more, implying that she would even consent to prostitute herself to make money for the traveling show, as others clearly have. Donna doesn't go that far, but Frankie does catch her in bed with Patch, straining the relationships of all three.