Rusty Sabich works as a district prosecutor in Chicago. Despite having a wife, he starts a secret affair with his colleague, Carolyn Polhemus. His life turns upside down when a horrifying murder case involving Carolyn is brought to the prosecutor's office, and Rusty is assigned to investigate it. Trying to keep the nature of their relationship a secret in order to save his marriage, Rusty only worsens the situation and soon becomes the prime suspect in the murder.