As the chief forensic anthropologist for the FBI's Chicago field office, Christine Prusik has worked her fair share of bizarre cases. Yet this one trumps them all: a serial killer is strangling young women and dumping their bodies in the steep, forested ravines of southern Indiana. With each victim, the killer leaves a calling card: a stone figurine carved like the spirit stones found among the primitive tribes of Papua New Guinea--the same tribes from whom Prusik narrowly escaped a decade earlier while doing field research. The similarity is eerie and, frankly, terrifying; Prusik still...