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.

In the wake of a disaster that wipes out most of civilization, two men and a young woman find themselves in an emotionally charged love triangle as the last known survivors.

Guided by a caller claiming to be a police officer, a manager begins an increasingly invasive interrogation of a young employee accused of theft.