Detailed Explanation
The Sinner is an anthology series where each season presents a new "whydunit" mystery. The connecting thread is Detective Harry Ambrose (Bill Pullman), whose own troubled psychology makes him uniquely suited to understanding why seemingly normal people commit terrible acts. Season 1 follows Cora's beach stabbing, Season 2 investigates a child's murder of his parents, Season 3 explores a fatal car crash, and Season 4 deals with a disappearance on a remote island. Each story is self-contained but explores the same theme: the darkness that lives in ordinary people.