The adventures of Mimi Paragon, cruise director on the S.S. Coronia, during a cruse to the Mediterranean. A younger man, Johnny Van Mier, quickly becomes romantically interested in Mimi, despite the disapproval of his mother, who is also on the cruise.
Also on the cruise is young Barnaby Slade. Barnaby immediately falls for Nancy Foyle, who is traveling as a companion and secretary for her aunt, a famous, acid-tongued novelist named Elinor Spencer-Bollard. Barnaby does his best to persuade Nancy to have a "beatnik love affair" with him.
Meanwhile, Mimi is having to deal with the various stresses and demands of her job. Perhaps most annoying to Mimi, who doesn't like children, is a particularly unpleasant child, Alvin Lush, and his only slightly less offensive mother.
By the time the Coronia returns home to New York, most everyone seems to be happy except Mimi, who has told Johnny that their relationship cannot work because of the difference in their ages. Just before the curtain falls, Johnny appears, looking for Mimi, and it's clear that their romance will happily resume.