A fast-paced psychological thriller by Freida McFadden that combines a serial killer mystery with family secrets and relentless suspense.

The story follows Nora Davis, a successful surgeon who has spent her entire adult life hiding a horrifying truth: her father was a notorious serial killer. As a child, Nora had no idea that while she was doing homework upstairs, her father was murdering women in the basement of their home. After his arrest, she reinvented herself, determined to ensure no one would ever discover her connection to him.

Years later, Nora's carefully constructed life begins to unravel when one of her patients is murdered in exactly the same gruesome manner as her father's victims. Suddenly, someone appears to know Nora's past—and is determined to frame her for a series of killings. As the police close in and the body count rises, Nora must uncover the real killer before she becomes the next victim or the prime suspect.

Filled with short chapters, shocking twists, and constant tension, The Locked Door explores themes of inherited evil, identity, trauma, family secrets, and the fear of becoming the person you despise most. It is one of McFadden's most popular standalone thrillers.