Some jockeys ride for the pay-off, Andy Crowley rides because she can't imagine doing anything else. On her way to becoming New York's most acclaimed female jockey, she's forced to move to a New England track renowned for colourful misfits and "accidental" deaths. After winning the unwinnable, she begins to suspect something's amiss. When an enigmatic owner insists the newcomer ride his Kentucky colt, she soon discovers how rough the races will get. She'll have to decide whether she can stay the course to her Derby dreams or get drawn into the dodgy and unpredictable world ruled by South Boston's mob bosses.