Five days ago, a homeless man on a subway platform died in agony as startled commuters looked on. Yesterday, a teenager started having violent, uncontrollable spasms in art class. Within minutes, she too was dead.

Dr. Alice Austen is a medical pathologist at the Centers for Disease Control in Atlanta. What she knows is that the two deaths are connected. What she fears is that they are only the beginning. . . .

"Manages to grab you with the authenticity of its scientific detective work and haunt you with its sheer plausibility."--Entertainment Weekly