Rusty Sabich, a district prosecutor in Chicago, finds himself entangled in a precarious situation when he embarks on a clandestine affair with his colleague, Carolyn Polhemus, despite being married. However, his life takes a drastic turn when a gruesome murder case involving Carolyn lands on his desk, and he is tasked with investigating it. In a desperate attempt to preserve his marriage, Rusty tries to conceal the true nature of their relationship, but instead, he inadvertently exacerbates the situation, ultimately leading to him becoming the primary suspect in the murder.