In the fictional suburb of Easttown, Philadelphia, police detective Marianne "Mare" Sheehan investigates the recent murder of a teenage mother while trying to keep her own life from falling apart.
A detective sergeant tries to solve a local murder case that threatens to tear a small town in Pennsylvania apart. In addition to the complicated investigations she also has to fight for the control over her personal life.
Mare visits a gruesome crime scene before informing the victim's father. Also, Mare interrogates suspects and unkindly greets county detective Colin Zabel who has been brought in for her assistance.
While Mare and Colin analyze new physical evidence, a recorded call leads to a an unlikely suspect. After Mare attacked Helen because of a a possible custody battle she receives advice by Richard.
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. Meanwhile, an anonymous call gives Dawn hope that Katie might still be alive.
Mare tells of her family history during therapy sessions. Lori tries to get to the bottom of her son's outburst at school. Mare meets with a source to find a possible connection between the cases.
Mare returns to work and immediately takes care of the murdered girl. During investigations the victim's bike is found in the river and the policewoman has to face the demons of her past.
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.
