The story begins one spring morning in New York City when a seventeen-year-old student wakes up feeling vaguely ill. She seems to be coming down with a cold. Hours later she is having violent seizures and has begun a hideous process of self-cannibalization. She is soon dead. When other gruesome deaths of a similar nature are discovered, the Centers for Disease Control in Atlanta sends a pathologist, an expert in epidemiology, to investigate. What she finds precipitates a federal crisis.

The details of this story are fictional, but they are based on a scrupulously thorough inquiry into the history of biological weapons. Preston's sources for his story include members of the FBI and the United States military, public health officials, intelligence officers in foreign governments, and scientists who have been involved in the development and testing of strategic bioweapons. His account of what they have seen and what they expect to happen and how they plan to deal with it is chilling.