The film opens at a carnival with two barkers calling for onlookers to enter the tent where an audience member will fight one of the professional boxers. In a setup, a trained amateur boxer takes the ring and knocks out one of the pros. The boxer, Johnny Flanigan played by Tony Wright, impresses the carnival promoters such that they take young Flanigan under their wings in an attempt to launch a comeback into prizefighting. Enter Giuseppe Vecchi a wealthy Italian with the connections to back the fighter. Flanigan's future looks promising until he meets Giuseppe's wife Lorna Vecchi. Lorna, played by Barbara Payton, married her rich and doting husband when he owned a club where she was a dancer. She's a true trophy wife all too eager to show her displeasure at her jovial husband's eccentricities. The first time Flanigan lays eyes on Lorna it's clear he is ripe for seduction. And seduction is clearly on Lorna's mind, evident as she licks her lips while her eyes scan Flanigan's shirtless, sweaty body after a bout. He may beat opponents in the ring, but Flanigan doesn't stand a chance against Lorna. Lorna gets what she wants and soon she's embroiled in an affair with Flanigan. Determined to make herself a wealthy widow, she begins enticing her lover in a plot to kill Giuseppe. Two murders follow, both orchestrated by Lorna. She gets her comeuppance, but only after ruining everyone's friendships, family and future. She's one bad blonde.