If you’re looking for a crime thriller that keeps you guessing until the very end, The Sinner deserves a place on your watchlist. Starring Jessica Biel and Bill Pullman, the psychological mystery series takes a fascinating approach to crime: instead of asking who committed the crime, it focuses on the far more disturbing question of why.

The first season begins with Cora Tannetti (Jessica Biel), a young mother who appears to have a happy family life. During an ordinary day at the beach, she suddenly commits a shocking act of violence against a stranger. The incident unfolds in public, leaving witnesses horrified — but what makes the case so unusual is that Cora herself seems unable to explain what drove her to do it.

Detective Harry Ambrose (Bill Pullman) becomes increasingly interested in the case. Although Cora’s involvement appears clear, he suspects there is something much deeper behind the incident. As he investigates her past, he begins uncovering painful memories and secrets that could explain what really happened.

What makes The Sinner stand out is its focus on psychological tension, complicated characters and carefully revealed mysteries. Rather than relying solely on traditional detective storytelling, each season explores a different case while continuing to follow Ambrose and the personal struggles that shape his investigations.

The series also features an impressive supporting cast, including Carrie Coon, Matt Bomer, Christopher Abbott and Frances Fisher. Across four seasons and 32 episodes, the story moves through several unsettling investigations, each with its own atmosphere and unexpected revelations.

Originally developed by Derek Simonds, the first season is based on the novel The Sinner by German author Petra Hammesfahr. The show went on to become an acclaimed psychological crime drama, earning strong reviews for its performances and distinctive storytelling.

For viewers who enjoy dark mysteries, layered characters and stories that gradually reveal their secrets, The Sinner offers a compelling binge-watch. All four seasons are listed on Netflix in Germany, although availability may vary by country.