Broadway producer Jerry Flynn is anxious to recapture the magic and reclaim the crowds after a set of costly flops. Outside his theater one night, Flynn meets a young boy who just might save the day. Inside a small box the boy shows Flynn his pride and joy: a caterpillar named Curly that dances to Yes Sir, That's My Baby. Word quickly spreads about the amazingly talented hoofer, and the caterpillar becomes a symbol of hope for wartime America. Soon, offers are pouring in to capitalize on this sensational insect.

A young American girl visits Paris accompanied by her fiancee and her wealthy uncle. There she meets and is romanced by a worldly novelist; what she doesn't know is that he is a blackmailer who is using her to get to her uncle.