It's June in Montreal, and Dr. Temperance Brennan, who has left a shaky marriage back home in North Carolina to take on the challenging assignment of Director of Forensic Anthropology for the province of Quebec, looks forward to a relaxing weekend in beautiful Quebec City. First, though, she must stop at a newly uncovered burial site in the heart of the city. The remains are probably old and only of archeological interest, but Tempe must make sure they're not a case for the police. One look at the decomposed and decapitated corpse, stored neatly in plastic bags, tells her she'll spend the weekend in the crime lab.

Four young women have been found murdered—tortured and strangled in their own beds—all victims of the same brilliant monster. Using a skilled hand and the latest technology in forensic medicine, Kay Scarpetta begins the process of gathering the microscopic clues the latest battered body has to give.

Relentless phone calls interrupt the peace of a warm August morning in Three Pines. Though the tiny Québec village is impossible to find on any map, someone has managed to track down Armand Gamache, head of homicide at the Sûreté, as he sits with his wife in their back garden. Reine-Marie watches with increasing unease as her husband refuses to pick up, though he clearly knows who is on the other end. When he finally answers, his rage shatters the calm of their quiet Sunday morning.

From Atlanta's wealthiest suburbs to its stark inner-city housing projects, a killer has crossed the boundaries of wealth and race. And the people who are chasing him must cross those boundaries, too. Among them is Michael Ormewood, a veteran detective whose marriage is hanging by a thread and whose arrogance and explosive temper are threatening his career. And Angie Polaski, a beautiful vice cop who was once Michael's lover before she became his enemy.

One look at the decomposed and decapitated corpse, stored neatly in plastic bags, tells Temperance Brennan she'll spend the weekend in the crime lab. Something about the crime scene is familiar to Tempe: the stashing of the body parts; the meticulous dismemberment. As a pattern continues to emerge, Tempe calls upon all her forensic skills, including bone, tooth/dental, and bite mark analysis and x-ray microflourescence to convince the police that the cases are related and to try to stop the killer before he strikes again.