The film begins in 1881 at Stavoren, a small Dutch rural town, and follows Katie\'s family to Amsterdam, where they hope to escape grinding poverty by finding work. Upon their arrival Katie secures employment at a dye-works, but is fired when she refuses to have sex with the director. She finds a job at a hat shop, where, during a business trip to a brothel, she discovers her older sister Mina working there. Later that evening, back at the hat shop, she is brutally raped by the owner and, in revenge, smashes the shop window.
Weeks go by, during which Katie\'s father works in a factory on low pay and Mina descends into alcoholism. While attempting to steal bread, Katie is knocked unconscious by a policeman and taken to a sanitorium. It becomes apparent that her body is her only asset as a doctor diagnoses tuberculosis, but refuses treatment unless she sleeps with him. It is unclear whether this occurs, but on her discharge Katie rejoins her family and discovers her father has been sacked and her sister is too drunk to sleep with clients. Katie\'s mother decides that, rather than the family starve, Katie must also go into prostitution.
Her first client is a gentleman, who Katie does not satisfy due to her inexperience. Her second client, an artist called George, takes her to his studio to pose for a painting depicting a Socialist revolution. He pays her the rate they negotiated for her services, but tells her he only wants her to model. He introduces Katie to Hugo, a banker, and Andre, a wealthy socialist, and they head to a nightclub for a meal. Katie\'s re-education has begun. Andre is attracted to Katie, but she seems enamoured with Hugo, with whom she goes home and sleeps. Hugo provides Katie with money for a new dress and they arrange to meet in the park. It is here that Katie\'s former life threatens to catch up with her when the gentleman she approached a few days earlier recognises her and informs Hugo he knew Katie when she only cost fifty pence. Hugo punches him, refusing to believe his story and promises Katie that she can move in with him \"forever.\" Katie goes to see her family, informing them she intends to leave. Her mother asks how she will feed the children if Katie\'s not there to provide. Katie tells her mother she \"should have fucked less\" and storms out, kicking her hysterical mother out of the way.
Once at Hugo\'s, Katie settles into the life of the bourgeoisie but is soon troubled at having to go spying on some of Amsterdam\'s less affluent shop owners to see who Hugo should refuse credit to. After being exposed in a coffee shop, and as a result, hot chocolate is thrown in her face, Katie tells Hugo she will not do his dirty work anymore. Very soon Hugo informs Katie that he intends to marry his fiancée and Katie must leave, stressing that their relationship was just a bit of fun that went too far. Katie, with nowhere to go, runs out onto the street and joins in a socialist march. The police arrive to break it up, opening fire on the marchers. During the confusion, Katie is reunited with George and Andre who are also present. Andre is shot in the arm and collapses, hitting his head. George takes them to a carriage waiting nearby and Andre and Katie board it, taking them to Andre\'s country mansion. Katie stays with him and, when he awakes, it becomes apparent that romance will blossom between the two. They discuss the subject of money, Katie telling Andre that \"money turns people into bastards.\" When Andre\'s headwound begins to bleed, Katie informs Andre that the best cure is to suck the blood. \"That\'s better,\" she says, a sliver of blood running from the corner of her mouth. The picture freezes and a roller-caption appears informing us that the film is based on true events from the life of Neel Doff and that \"her indomitable spirit lives on in this film.\"
