Book editor Sarah Stanforth dreams of vengeance against Erica Tudor, the stunning young author her husband Keir has fallen in love with. But she is unprepared when, out of the blue, Erica arrives at her isolated farmhouse brandishing a gun. During a violent struggle, Sarah reaches for an ax, and brutally hacks her rival to death. Knowing no one will believe she killed Erica in self-defense, Sarah secretly buries the body in her backyard. And now, caught in a terrifying spiral of guilt and paranoia, she will do anything to avoid discovery.