Jerry Mulligan is an exuberant American expatriate in Paris trying to make a reputation as a painter. His friend Adam is a struggling concert pianist who's a long time associate of a famous French singer, Henri Baurel. A lonely society woman, Milo Roberts, takes Jerry under her wing and supports him, but is interested in more than his art.
Ellen McNulty leaves her New Jersey hamburger stand and heads west to pay a surprise visit to her son and his new bride. When Ellen arrives, her daughter-in-law mistakes her for the maid she has hired for a big party they are throwing. Rather than cause any embarrassment, Ellen goes along with the charade, which leads to many complications.
Sandra Carpenter is a London-based dancer who is distraught to learn that her friend has disappeared. Soon after the disappearance, she's approached by Harley Temple, a police investigator who believes her friend has been murdered by a serial killer who uses personal ads to find his victims. Temple hatches a plan to catch the killer using Sandra as bait, and Sandra agrees to help.
Shortly after Pearl Harbor, a squadron of PT-boat crews in the Philippines must battle the Navy brass between skirmishes with the Japanese. The title says it all about the Navy's attitude towards the PT-boats and their crews.
Hat check man Louis Blore is in love with nightclub star May Daly. May, however, is in love with a poor dancer but wants to marry for money. When Louis wins the Irish Sweepstakes, he asks May to marry him and she accepts even though she doesn't love him. Soon after, Louis has an accident and gets knocked on the head, where he dreams that he's King Louis XV pursuing the infamous Madame Du Barry.