Fatal by John Lescroart

A tense standalone thriller set in San Francisco, Fatal explores how a single impulsive decision spirals into a deadly chain of events. When Kate Jameson admits to her best friend, police detective Beth Tully, that she has become dangerously fixated on a married man she recently met, Beth is shocked by the confession—yet unaware of how far the obsession will go. One brief encounter leads to consequences neither woman could anticipate. Six months later, the man at the center of Kate’s infatuation, Peter Ash, is found dead on a beach, and Beth is assigned to the investigation. As she delves into Peter’s complicated final months, the circle of suspects tightens, revealing how little we truly know about the people closest to us. Blending psychological tension with a steadily unfolding mystery, the novel follows the destructive power of secrets, desire, and the lies we tell to protect ourselves.