Kay Scarpetta has arranged to meet an inmate at the high-security Georgia Prison for Women. The prisoner is a convicted sex offender and the mother of a vicious and diabolically brilliant killer. Against advice, Scarpetta is determined to hear this woman out - she believes she may hold some answers to the murder of her former deputy. But soon she finds connections to a string of grisly killings, including the slaughter of a Savannah family years earlier. She can see a pattern to these killings, but who is behind them and why?