The U.S. government is conducting a top secret experiment referred to as Project Noah, which involves acquiring and transporting death row inmates to a secret military compound in Colorado for the purposes of testing a drug intended to greatly prolong life. These genetic experiments originate from patient zero Fanning - one of two surviving members of an expedition investigating a Bolivian bat-carried virus. The virus, while causing hemorrhagic fever and death in those who initially contracted it, is resulting in a boosting of the immune system, and enhanced strength and agility in the current subjects.The FBI agents responsible for recruiting the prisoners are ordered to collect 6 year old Amy Bellafonte from a convent, and, although conflicted, deliver her to Dr. Lear, the head of the project. At Noah she is exposed to a refined version of the serum administered to The Twelveâ€”the original inmates. Lear theorizes that as Amy's immune system has not had chance to mature it will form a symbiosis with the virus and live with her symbiotically, instead of the violent forms it has taken with the other twelve.Of the inmates, the first and last recruited are depicted as being different from the others: Babcock, the original test subject, is stronger and appears to have developed psychic abilities, occasionally influencing his guards and cleaners and Carter is in fact innocent, but was convicted of first-degree murder nonetheless.Zero (AKA Fanning) and the other twelve inmates mentally take control of their guards and escape their quarantine cells, rapidly killing all who stand in their way. Amy is rescued by Brad Wolgast (the FBI agent who brought her to Noah) and Sister Lacey (a nun who was looking after Amy when she was recruited). Lacey is taken by Carter, as Wolgast and Amy escape to a mountain retreat where they live for several months, occasionally picking up news of the contagion spread throughout America. The rest of the world's fate is not stated, but it is mentioned that most of Europe has imposed quarantine over travel.Despite living reasonably comfortably in the mountain site, Wolgast eventually succumbs to radiation sickness when a nuclear device is detonated relatively nearby - he assumes that the government is attempting to sterilize infected areas of the country - and Amy is left to fend for herself.