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.
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.
After a demonstration of new PT boats, navy brass are still unconvinced of their viability in combat, leaving Lt. "Rusty" Ryan frustrated. After the attack on Pearl Harbor, however, Ryan and his buddy Lt. Brickley are told they can finally take their squadron into battle. The PT boats quickly prove their worth, successfully shooting down Japanese planes, relaying messages between islands, and picking off a multitude of enemy ships.
