Jeff Bailey, the protagonist of the movie, is like a typical noir charcter in that he is a sardonic private investigator. He is used by Kathie and is betrayed by her. He seems to be an almost tragic sort of character, a look of gloom always on his face. He seems at first to be an introverted sort of character but he puts his love for Ann ahead of himself which ultimately leads to his demise in that he sets up Kathie and pays for it with his life.
Kathie is very much so the typical femme fatale that you'd find in film noir. She is a seductress. She relies on her sexuality to get what she wants. She is the possession of an older extremely wealthy husband, who buys her in a way. She is a murderer and she is ruthless. She also seems to lack any sort of morality. Greedy and self indulgent, she always tries to make people feel bad for her when she gets herself into a tight or compromising situation. Her manipulative ways help her hide from Whit with Jeff for awhile, but soon enough Jeff sees what kind of person she really is, a lethal seductress who cares about no one but herself.
Ann is your typical film noir lady in that she is the dutiful and loving woman who Jeff is in love with. She puts her complete trust in Jeff when he tells her he has to leave to meet the girl he used to be in love with. In the end she is told a lie to leave Jeff in the past and to move on with her future.
Whit , the slick racketeer, doesn't trust anybody. All he cares about is having Kathie back, as if she were property of some sort. A man, who although might seem to be pretty decent, what with not having hurt Kathie after she tried to kill him and took $40,000 from him, is actually rather manipulative, setting up Jeff as the fall guy for a murder he didn't commit.
The themes in this film are betrayal, passion, double-crossing, greed, guilt, and doomed fate. Betrayal is experienced by Jeff when he realizes that Kathie was lying to him the whole time about not having taken the money, and also when she plays her part in trying to set up Jeff for Eels murder. Passion is shown throughout the film; Jeff's love for Kathie is shown during a rendezvous at the beach, and Jeff's undying love for Ann is shown in the forest when they see eachother for the last time. Double-crossing is a major theme in the movie. Jeff double-crosses Whit when he runs away with Kathie, Whit double-crosses Jeff when he frames him for Eels murder, Jeff double-crosses Kathie at the end when he turns her over to the police, so on and so forth. Greed is shown through Whit when he has to have Kathie back, even after she tried to off him. Guilt is shown though Jeff, and how he feels bad about mixing up a good gal like Ann into his sordid affairs. Doomed fate is also a major theme, shown in the flashback, when it sounds like Jeff's narration is the voice of fate. It seems like he knew about his demise and his bad ending from the first moment he met Kathie. Tourneur shows the themes in cinematic elements as well. For example, when...