Sarah Green, a 62-year-old matron, returns to college to become more educated and sociable. During her first day of college, "Mrs. G" discovers that she has a lot to learn--and a lot to contribute.
Everyone leaves campus on Sunday. Mrs. G's Sunday plans to visit her family are spoiled when her son-in-law's mother becomes ill. She wanders the campus looking for someone to share her Sunday leg of lamb.
Mrs. G is about to flunk chemistry, taught by nasty Professor Kestner (Peter Lorre), who even urges her to drop out, but her advisor Professor Crayton (Cedric Hardwicke) bucks her up and encourages her to give it the old college try.
Mrs. G begins to teach a free informal class in Western Civilization to her working-class neighbors, but she becomes so involved in this project that she starts to neglect her own college coursework.