Dr. Kay Scarpetta is newly returned from Dublin, where she was called in to examine the remains of a murder victim whose limbs and head were expertly severed - a signature of a cunning serial killer on the loose again after an eight-year sabbatical - when the same killer apparently strikes again, this time much closer to home. After Scarpetta investigates the murder scene, the killer boldly contacts her through the Internet, inviting her to download photos of the murder victim and signing off with a chilling screen name: deadoc.
When Scarpetta determines that the victim was exposed to a rare smallpox-like virus before she died and, later, that she herself may have been infected, she realizes that she is up against a killer with access to an incredibly sophisticated arsenal of deadly force - a killer with a specific animus directed toward her.