THE NOTORIOUS LANDLADY: When her husband disappears, Carly Hardwicke (Kim Novak) finds it impossible to rent a room in her London apartment, since everyone assumes she's a murderer. Recently arrived American diplomat William Gridley (Jack Lemmon), however, has no idea about her reputation. Sparks fly between the pair, and Gridley rents the room. When his boss, Franklyn Ambruster (Fred Astaire), learns what Gridley has blundered into, he reproves him until he meets the lovely Carly. The two men try to clear her name.
UNDER THE YUM YUM TREE: The lustful Hogan (Jack Lemmon) is a landlord who prefers to rent his rooms to attractive single females. Hogan is instantly smitten with a pretty new tenant named Robin (Carol Lynley), but realises that he'll have to contend with Robins boyfriend, David (Dean Jones), if he's to attain the object of his desire. He gets his opportunity when he learns that the couples living arrangement is a pre-marital experiment to see if they would be compatible as partners when sex is out of the equation.