When Beth Emhoff returns to Minneapolis from business in Hong Kong, what she thought was jet lag takes a virulent turn. Two days later, she's dead in the ER and the doctors tell her shocked and grieving husband they have no idea why. Soon more cases are reported as the virus begins to spread. Researchers mobilize to break the code of this unique biological pathogen as it continues to mutate. Deputy Director Cheever tries to allay the growing panic despite his own personal concerns, and must send a brave young doctor into harm's way. As the death toll escalates and people struggle to protect themselves and their loved ones in a society breaking down, one activist blogger claims the public isn't getting the truth about what's really going on, and sets off an epidemic of paranoia and fear as infectious as the virus itself.