On a sunny summer afternoon by the lake, Cora Bender stabs a complete stranger to death. Why? What would cause this quiet, kind young mother to commit such a startling act of violence in front of her family and friends? Cora quickly confesses and it seems like an open-and-shut case. But the police commissioner, haunted by these unanswered questions, refuses to close the file and begins his own personal investigation. So begins the slow unraveling of Cora's past, a harrowing descent into the depths of her psyche and the violent secrets buried deep within.