When Christy Murphy comes home past midnight with her boyfriend, Jerry, her parents send her to the Academy of the Blessed Virgin, a Catholic school run by kind but very strict nuns.

As America's stock of athletic young men is depleted during World War II, a professional all-female baseball league springs up in the Midwest, funded by publicity-hungry candy maker Walter Harvey. Competitive sisters Dottie Hinson and Kit Keller spar with each other, scout Ernie Capadino and grumpy has-been coach Jimmy Dugan on their way to fame.