A serial killer is on the loose in Richmond, Virginia. Three women have died, brutalised and strangled in their own bedrooms. There is no pattern: the killer appears to strike at random - but always early Saturday mornings. So when Dr Kay Scarpetta, Chief Medical officer, is awakened at 2.33 am, she knows the news is bad: there is a fourth victim. And she fears now for those that will follow unless she can dig up new forensic evidence to aid the police. But not everyone is pleased to see a woman in this powerful job. Someone may even eant to ruin her career and reputation ...