A young Broadway producer, Gary Blake (Dick Powell), is busy putting together his latest big-time musical starring Mona Merrick (Alice Faye). Mona's role as "The Richest Girl in the World" is a pointed impersonation of Park Avenue socialite Mimi Caraway (Madeleine Carroll), who catches a performance and becomes enraged at what she sees. Mimi goes backstage to complain to Gary about Mona's performance. Gary is swept off his feet but the young debutante and agrees to tone down the role. The thing is, Gary used to go out with Mona, and Miss Merrick isn't so keen on the "agreement". When Mimi and her family come to the next performance, they are met with a performance from Mona that is even more nasty and self-centred than before. Incensed and out for retribution, Mimi and her family buy out the production and Mimi makes changes that make Gary wake up and realise that this pretty face is killing his show.