Based on Somerset Maugham's story, a fanatical reformer in the South Pacific insists that a sexy woman go back to San Francisco and face prison.
A boat from San Francisco brings to Pago Pago the reformers Alfred Davidson (Lionel Barrymore) and his wife (Blanche Friderici), tolerant Dr. Angus McPhail (Charles Lane) and his wife, and the vivacious Sadie Thompson (Gloria Swanson), who is welcomed by marines. Her boat to Apia is delayed because of quarantine, and she stays in the hotel storeroom.
Sadie gets marines to fix up the room. She plays a record, and the men dance. Davidson implies that she is a prostitute, but the marines throw him out of her room. Sergeant Tim O'Hara (Raoul Walsh) talks with Sadie alone. He comes back and warns her that Davidson intends to make trouble for her and him.
It continues to rain. Davidson offers Sadie the gift of salvation and asks what she did in San Francisco. She says she was a singer. He says he will keep her from going to her job in Apia. He grabs her by the wrists and makes her kneel. She breaks free, and he says he is going to the Governor.
O'Hara comes to see Sadie and shows her his photo album. He suggests that she go to Sydney. Sadie is given an order to go back to San Francisco. She says she can't go back. Davidson comes in, and she yells at him. O'Hara holds her back, and they leave. Sadie talks to the Governor, and O'Hara carries her in the rain. O'Hara is told to report to the skipper. Sadie tells Davidson that the Governor said she could go to Sydney if he approves. She says a man in San Francisco won't let her go straight. She admits it is the law but says she was framed. Davidson says that she must go back and to prison. Sadie appeals to Dr. McPhail, who talks with Davidson to no avail. She asks Davidson for mercy but gets none. Sadie becomes frantic and cries out to Davidson. She says she is afraid, and he tells her to repent and pray. She says she does not know how, but she repeats his words.
After three lonely days of her repentance, O'Hara gets out of confinement and comes to the hotel. He tells Sadie that she can take a fishing boat, and he has two men load her stuff. He says she can repent in Sydney, but she says she has been saved and wants to go back. O'Hara carries her, but he is stopped by Davidson and two men. O'Hara shakes her hand and leaves. She asks Davidson not to harm O'Hara. Davidson tells her that she has rejected Satan.
Davidson tells his wife and Dr. McPhail that Sadie has been reborn. Mrs. Davidson tells Dr. McPhail that her husband had bad dreams about Sadie.
At night Davidson finds Sadie sitting up and says she does not have to go back to San Francisco and that she is beautiful.
In the morning natives find a body in the sea. Dr. McPhail says that Davidson killed himself. O'Hara tells Sadie that his service ends in four weeks and asks her to wait and go to Sydney with him. She says she will.
This drama portrays a religious fanatic who interferes
in someone else's life so much that it ruins his own. The setting
reflects the historic contrast between the free spirits of Pacific
natives and the zealous missionaries who have tried to "save"