One of the richest men in Canada is shot dead in his Toronto mansion. The police are baffled. The victim's family call on Rachel Tile, head of the school of criminology at a Toronto university, to conduct an investigation. As the dead man's ex-wife, Rachel knows enough about his unethical business practices and callous cruelty to shed no tears over his murder, but reluctantly takes on the role. Struggling with pressure from the university to raise millions of dollars for her school, with her own depression and alcoholism, and with her husband's gambling addiction, Rachel is pushed to her emotional and intellectual limits as she searches for the killer. As more bodies begin to pile up, Rachel realizes she and her family may now be in the killer's crosshairs.