Thelma Jordon (Barbara Stanwyck), late one night, shows up in the office of married Assistant DA Cleve Marshall (Wendell Corey). Before Cleve can stop himself, he and Thelma are involved in an illicit affair. But Thelma is a mysterious woman, and Cleve can't help wondering if she is hiding something. Thelma has a plan up her sleeve that will ruin Corey if his love for her and his own weakness win out. Thelma has a heart and a conscience. She comes to love Cleve, and has concern for his life and his future. Despite her wish that her life could be different, she realizes that she belongs in a lawless world.