When Boston private investigator Patrick Kenzie meets Karen Nichols, she strikes him as an innocent from a protected upbringing. But six months later when Karen takes her own life, Patrick is left wondering what can change so drastically and so quickly that suicide seems the only option?As the stakes grow higher and more personal, they find themselves fighting a losing battle with an enemy the law can't touch, who is always one step ahead, who is gradually discovering their weaknesses, their loves, and is determined to tear their world apart.