A smoking, jazz-loving young prostitute named Sadie Thompson Gloria Swanson arrives at Pago Pago (American Samoa), en route to a job with a shipping line on another island. At the same time, “moralists” arrive, including Mr. Davidson Lionel Barrymore and Mrs. Davidson Blanche Friderici. They all end up staying in the same hotel, where the Davidsons plot to teach the natives about sin and Sadie entertains a crowd of Marines.
Sadie begins to fall in love with Sergeant Timothy “Tim” O’Hara Raoul Walsh, who isn’t fazed by her past. He tells her that he has a best friend who married a former prostitute, and the couple now lives happily in Australia. The two characters form a fragile bond as the social clash around them intensifies.
Davidson sets about trying to redeem Sadie, using sly coercion to pry at her past in San Francisco. When she refuses to repent, he declares that he will go to the governor and have her deported. Sadie is terrified by the threat, but O’Hara offers reassurance and hopes she would go to Australia to wait out his term so they can marry afterward. She agrees, though the threat lingers.
Davidson manages to push his plan forward, and Sadie grows increasingly furious. She and O’Hara go to the governor, begging to let her go to Australia instead of returning to San Francisco. Davidson has managed to have O’Hara punished for immorality, but Sadie could still go to Australia if Davidson approves. She pleads, and finally confesses that if she returns to San Francisco there is “a man there who won’t let her go straight.”
> "a man there who won't let her go straight"
Davidson explains that true repentance would require prison, and Sadie pleads against it. She runs to her room in tears, while Davidson returns, and Sadie confesses her fear. Davidson then offers the possibility of repentance through sanctification, and Sadie converts to Christianity.
Sadie prays for three full days, cleansing herself of the old life and becoming a modest woman. O’Hara returns to find Davidson missing, apparently “trying to stop the locals from dancing on the beach.” He reveals that he has a fishing boat ready to take Sadie and her belongings to a ship bound for Australia, where they can marry and be free. Sadie, shaken, insists the “old Sadie is dead” and prefers San Francisco and prison to repent.
O’Hara does all he can, including forcing her from her room, but Davidson waits outside. O’Hara attempts to intervene, but Sadie pleads for him to stop. He leaves, deeply troubled, and Sadie begs Davidson not to jeopardize him—for “it was all her fault.”
Later that night, as everyone else heads to bed, Davidson wanders the rain-soaked streets, haunted by dreams about Miss Thompson. A fellow boarder hints they are not as unpleasant as they seem. Davidson confronts his own conflict, realizing he is drawn to Sadie in a way he cannot control, and he glances into her window before retreating.
Sadie, frightened by noises, waits in Davidson’s room, and he is startled to find her there. He sends her back to her own room, and the tension between fear, desire, and duty hangs in the air.
The last reel of the film is missing, but the original story concluded with the fishermen discovering Davidson’s body—suicide. In the surviving narrative, Sadie and O’Hara reconcile and head toward Australia, choosing a future together over the pressures of the past.
