Tommy McCoy (Mickey Rooney), a young man from the slums of New York City, is a rising lightweight boxing star. His success helps him support his alcoholic father, Brian (James Dunn). Tommy sees the dark side of boxing when he gets involved with gambler Jim Caighn (Brian Donlevy), who intends to rig Tommy's fights. To make matters worse, Tommy falls in love with Jim's daughter, Sheila (Ann Blyth). A big fight is imminent, and Tommy must decide if he will continue to play Jim's treacherous game.