When her investigation takes a series of devastating turns, Mare's friends and family members process the fallout as she attempts to finally find her own way forward.

In her mandated therapy, Mare opens up about her family’s history with mental health struggles. Meanwhile, Lori tries to get to the bottom of her son’s outburst at school, and later, Mare meets with a semi-retired source to help find a possible connection to her three cases.

After answering a call about a neighborhood prowler, Detective Mare Sheehan shoulders her chief’s directive to revive an unsolved missing person’s case amid increased community pressure. Later, while her loved ones celebrate her ex-husband Frank’s engagement, Mare attends a celebration for her legendary high school basketball win and connects with Richard, a professor who’s new in town.

As Mare and Colin parse new physical evidence, phone records lead to an unlikely suspect. After lashing out at Helen about a possible custody fight over Drew, Mare receives some unprompted advice from Richard on how to move forward with Carrie. Later, Kenny and Mare face the consequences of their misguided attempts to protect their families.