Stephen Pearse and Peter Maryk are doctors who once worked together to research a horrifying virus outbreak in the Congo. Now Pearse heads the Bureau of Disease Control, and Maryk runs the clandestine special pathogens section of the disease detectives—making the two scientists bitter enemies. But when the disease from the Congo re-emerges in America, they must set aside their differences in order to stop a potential worldwide epidemic. Using the blood of one woman who is immune to the disease, they create a serum that might work—if the disturbingly cunning virus doesn't have plans of its own.