Patty gets a part in a play but learns it's heading to NYC for a Broadway run. Eddie gets Heather a job as a receptionist at a modeling agency experience culture shock due to the less formal ways of Americans.
Patty gets sick and needs a doctor. But her parents Eddie and Dorothy insist the Finchs get an American physician for their daughter. Tommy takes on the difficult task for his old friend.
Heather bumps into an English man Ronald at an automat and is berated for being a clumsy, rude American. Over in London Patty befriends a newly arrived American family but her motives are questioned.
After seeing their most recent phone bills both Tommy and Eddie separately declare no more transatlantic calls. But when Patty wants to go to Paris and Heather needs major dental work the need for personal communication seems necessary.
Eddie surprises Dorothy with a trip to London to see their daughter Patty. But staying with the Finchs is a problem as Tommy's Aunt Nell is visiting and she doesn't care for Americans.
Instead of spending time with each other the Walkers and the Finchs find themselves in each other's countries. Without someone to show them around both families have a series of misadventures.