After losing his job as a stoker on a luxury cruise liner, the resentful but ambitious Jim Carter (Spencer Tracy) joins a carnival run by Pop McWade as a cleaner for a show called Dante’s Inferno. Acting as barker, Jim plays up the sensational aspects of the glimpse into hell and brings in a large audience, to Pop’s delight. After marrying Pop’s niece, Betty (Claire Trevor), Jim is consumed with turning the show into a spectacular, and leads his family to the brink with his obsession.