Jan Morrow is a successful, self-reliant interior decorator in New York City. She lives alone and claims to be quite happy, when questioned on that subject by her drunken housekeeper, Alma. The only irritant in her life is the party line that she shares with Brad Allen, a talented, creative Broadway composer and playboy who lives in a nearby apartment building. She is unable to obtain a private phone line because the telephone company has been overwhelmed by the recent demand for new phone lines in the area.