4:23 a.m. The phone rings. The officer on the other end says, "It's a bad one, Darren. Can you come?" Darren McDaniel has worked dozens of homicides in his years as a detective. It's a dark and gritty business, and he's prepared to handle whatever it throws at him. Or so he once believed.The pre-teen girl is dead, dressed in a white princess gown, lying on a bus stop bench. There's a steel chain clamped to her ankle. A cryptic message scrawled...