Chicago racetrack publicist Jack Doyle, former advertising man and amateur boxer, accepts the challenge of a new job in the world of thoroughbred horse racingthat of jockeys agent. His client is a seventeen-year-old riding phenom from Ireland named Mickey Sheehan, who has decided to try her luck in the States. They prove to be an effective team until someone begins secretly administering dangerously illegal medications to horses, affecting race results .