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 on Saturday mornings.

So when Dr Kay Scarpetta, Chief Medical Examiner, is awakened at 2.33 a.m. she knows the news is bad: there is a fourth victim. And she fears now for those who 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 want to ruin her career and reputation...