Eliza thinks she has the perfect marriage, living in suburban Long Island with her husband Louis. However, the morning after Thanksgiving, she discovers what appears to be a love letter written to her husband. Distraught by the possibilities and seeking advice, she drives to her parents' house, where she shows the letter to her high-strung mother Rita, her mild-mannered father Jim, her rebellious younger sister Jo, and Jo's pretentious boyfriend Carl. Hoping to quickly resolve the situation, the five of them cram into the family station wagon and set off for Manhattan where Eliza can confront her husband face-to-face. They arrive at Louis' office only to discover that he has been given the day off. The family desperately tails Louis around the city, but always ends up one step behind him. As the day progresses, they find themselves gradually revealing their long-repressed feelings towards each other, and encounter a series of eccentric strangers whose problems mirror their own.