Her son Adam is in the middle of a fight against leukemia, and Rachel is determined to keep focused on that battle. But when humans begin picking sides and the fighting escalates, their home in Baltimore becomes a war zone, one she can’t ignore.
Desperate to stay away from the carnage—as well as the germ-ridden refugee center—Rachel and Adam flee to their remote mountain cottage, only to find their refuge marred by mutated, grotesque plants and animals. Eventually, the cancerous cells in Adam's body begin evolving as well, threatening his life and forcing Rachel to venture back into the eye of the storm. Left with no other choice but to sacrifice her own freedom for her son's safety, she must become an unwilling warrior in a battle unlike anything seen in millennia, or lose everything she holds dear.