Having just transferred from Milan, Inspector Soneri arrives in the town of Ferrara. On the River Po, an empty barge drifts downriver, the owner missing. The same night, Soneri is called to investigate the murder of the boatman's brother.
Investigating the murder of an old friend, Inspector Soneri finds he never really knew her. As he uncovers more about her illegal activities, it reveals a deeper mystery tied to his marriage, jeopardizing his new relationship.
When a former policeman is found dead, Inspector Soneri tries to discover what made a good cop go bad. During the investigation he ends up confronting Angela, who is defending a suspect.
A woman is killed in a movie theater. Then, with Angela's life in danger, Soneri finds himself investigating an all-female case, delving into the dark side of the women.
