Instagram model Marie Clark is getting her masters in comparative religion and moving on from an abusive past with the help of her psychiatrist, Dr. Brighton. It seems Marie's life is finally on the right trajectory until her diary is stolen and an obsessive fan begins sending her love letters informing Marie that they are killing anyone who they see as a danger to her. As friends begin to feel like suspects, and bodies start piling up, terrifying as it is, Marie must confront the demons of her past in order to unmask the killer and reclaim her life.

Madison Taylor (Merrin Dungey) is a forensic psychiatrist, spending her days interviewing prison inmates and her evenings with her husband Jeremy. When Jeremy is killed in a home invasion by Francis Tate (Devon Graye), her world begins to turn itself inside out.