Detective Mare Sheehan revives an unsolved missing person's case amid increased community pressure; 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.
With Mare forced to take a backseat on the case, Colin presses a local priest about the vague circumstances that prompted his transfer to the parish; an anonymous call gives Dawn hope that Katie might still be alive.
In her mandated therapy, Mare opens up about her family's history with mental health; Lori tries to get to the bottom of her son's outburst at school; Mare meets with a semi-retired source to help find a possible connection to her three cases.
After a heroic rescue lands her in the hospital, Mare awakes to the unshakeable pain of losing a friend. Then, given a second chance by Chief Carter, Mare reevaluates old suspects, which leads to a shocking clue.
When her case takes a devastating turn, Mare's family and friends process the fallout while she attempts to find her own way forward.