After young Mary Gibson (Kim Hunter) discovers that her older sister Jacqueline (Jean Brooks) has disappeared, she leaves her boarding school and heads to New York City to track down her sibling. Arriving at Jacqueline's apartment, Mary finds ominous signs of trouble, with her sister nowhere in sight. 

The wedding of Ellen (Claudette Colbert) and David (Robert Ryan) is halted by a stranger who insists that the bride is already married to someone else.

Harry Morgan is the owner-operator of a charter boat in wartime Martinique. He falls in love with a pickpocket who wants to go to America and so to help her he does the impossible.Closed-Caption

Scott Henderson's (Alan Curtis) innocuous evening with a strange woman becomes crucial when he is later accused of murdering his wife on the same evening. When Scott's story is disbelieved and a trial fails to bring forth the "phantom lady," Scott's devoted girl Friday, secretary Carol Richman (Ella Raines), begins her own investigation with the aid of police inspector Burgess (Thomas Gomez).