Prison drama in which an old timer and a younger, inexperienced woman are soon corrupted by their milieu.

Lina, a naive young woman, joins the company of prostitutes, murderers, and thieves at a large women's prison as she awaits her trial on charges of robbery. She soon finds a friend in Aggie, a hardened prostitute and con woman who decides to school Lina in the ways of the world. Lina tries to convince Aggie that she is innocent: she had come to Rome to work as a housemaid and had fallen in love with Adonis, who promised to marry her. One night they went to a movie; her employer's house was robbed while they were gone, and she was charged with the crime. Aggie insists that Adonis planned the crime. She advises Lina to offer him a proposition: her silence in exchange for a share of the "take." Lina learns that her cynical friend is right: Adonis is a married man with three children, and she is not the first housemaid Adonis has tricked. Acquitted of the crime, Lina leaves her innocence behind in prison. Meanwhile, Aggie's cynical defenses begin to waiver. She is moved by her contact with Marietta, a romantic young thief who has been watching a mechanic working across the street from the prison. Lina secretly brings them together; they fall in love and make plans to marry. Marietta leaves the prison, and Aggie considers the hopelessness of her life, happy that her friends are free. One day Lina returns to the prison transformed into a grotesquely painted prostitute. Aggie feels responsible for the change; in horror she attacks Lina. As she is being dragged off to solitary confinement, Aggie screams for the freedom to change her life.