A group of women have been discovered who are immune to the Agent X plague. The secret of their immunity can provide a cure for human and inhuman alike-unless the Xombies find them first.

Unconscious for fourteen months after a debilitating accident, Maddy Grant awakens at the Braintree Institute, where scientists have successfully implanted her with a radical technology designed to correct her brain injury. But Maddy is more than cured. Her intellect has been enhanced to process information faster than a computer-an ability that's sending her emotions into overdrive.

To monitor her condition, the institute sends Maddy to the nearby village of Harmony, where she will be free to interact with the community. But Braintree's scientists are not only monitoring her behavior, they're modifying it, reprogramming her personality to become someone else.

A killer.

Survivors of a cataclysmic zombie-making plague leave a temporary safety of a refitted nuclear sub to scavenge for food and supplies on land. But they soon find themselves facing new terrors on the surface and mutiny below.