Two families, the Walkers of New York and the Finches of London, adopt each other's teenage daughter for one year. Once settled in their new homes, the girls have some initial difficulties with the problems of homesickness and kid brothers, but each works out her own solution. Eddie Walker and the Finches have agreed to the exchange plan. Now all Eddie has to do is tell his wife about it.

On the British side of the Atlantic Patty and The Finch's deal gently with Neville's crush on Patty while the Walkers encourage Larry to attend the school dance. Heather teaches Larry the twist and he's soon going steady and talking endlessly on the phone. Neville is invited to join Patty and her friend Brian for an evening out,hoping is infatuation will fade.