A brilliant and dedicated psychologist, Grace Blades has a gift for treating troubled souls and tormented psyches - because she bears her own invisible scars. Only five years old when she watched her parents die in a bloody murder-suicide, Grace took refuge in her fierce intellect and found comfort in the loving couple who adopted her. But her now-accomplished life has a secret side, ruled by an insatiable desire; by night she pursues the addictive thrills of sexual trysts with strangers. And when her two worlds unexpectedly converge, Grace's past returns with a vengeance, threatening to destroy everything she's fought for - including her life.Shaken by the murder of her newest patient and fearful that an investigation will expose her double life, Grace sets out to probe the crime herself. But when she stumbles on the dead man's true identity, a horrifying chapter from her childhood is violently reawakened, forcing Grace to confront a decades-old act of evil crying out to be avenged. Suddenly stalked by dangerous men, Grace must turn to the talent for survival she's depended on all her life in order to face down the darkest personal demon she's ever battled: her own.