While attending a glamorous jazz cruise on New York’s East River, Nick and Nora Charles witness the fatal shooting of a wealthy patron. When suspicion falls on a young bandleader and his musicians, the couple steps in to clear their friends and uncover the real killer. Their investigation leads through a lively world of jazz clubs, radio personalities, high society, and backstage rivalries, where almost everyone has a secret and the next clue may be hidden in the music.