The story begins with an urgent phone call from the remote rain forests of the Congo. Drs. Stephen Pearse and Peter Maryk are summoned to a mining camp where a deadly virus has killed everyone within its reach. Desperate to stop it, they bomb the area, resealing a uranium cave that had housed and nurtured the virus for centuries. Two years later, the disease reemerges in America, devastating the small New England town of Plainville. Stephen Pearse is now head of the FBI-like Bureau of Disease Control; Peter Maryk, a man gifted with a highly advanced immune system, now runs the bureau's clandestine special pathogens section of disease detectives. Since their return from Africa, the two men have become bitter enemies divided by opposing scientific philosophies. But together they must track down the virus as it continues to spring up in isolated incidents, each time becoming increasingly calculating, cunning and human-like as it drops its plague across the landscape. The battle intensifies as it becomes clear that the Plainville virus is being spread by one particular human host - giving the virus a name and a face. Their search involves the last survivor of the Plainville outbreak, a young woman, who is now immune to the virus. Her blood is the serum of life in the face of viral death, making her a critical target. Pearse and Maryk must keep her safe, while formulating a plan to get to the killer before he gets to the woman.