Uncle Charley, Robbie, and Katie from "My Three Sons" visit Rome and the Endicotts. Uncle Charley enlists Mike's help in finding a girlfriend from World War I, while Robbie and Katie hope to enjoy a second honeymoon.

A nightclub proprietress who sings plays a mysterious role in the Endicotts' sudden streak of good fortune.

Grandpa plays a key role in a battle between the Endicotts' fellow tenants and their anonymous landlord.