When Abby Northrup's best friend, Marti Bright, is found nailed to a homemade wooden cross on a windswept hill in Carmel, California, Abby is thrust into a nightmare she may never escape from alive. Compelled by grief and shock, she begins to piece together what happened to the woman she loved like a sister. With her marriage to an influential politician in tatters and her "perfect life" only a carefully fabricated illusion, Abby focuses instead on Marti - probing their past, the time the two friends spent in a convent, and the secrets they'd kept all these years. But as Abby reaches further and further into the maze of Marti's last days, she realizes that the woman she thought she knew so well was keeping secrets from her - and that her own life is linked to her friend's in ways she never imagined . . . in ways that could make her a vengeful killer's next victim.