Jacob Hood and Rachel go to northern California to investigate why almost an entire family ended up paralyzed and near death after eating breakfast. Initially the teenage daughter is a suspect because she has escaped her family's fate, but Hood knows that's not possible, since she wouldn't have the knowledge and what happens seems to be more related to what they ate. After finding a giant fungus growing out of the family's dead dog's stomach, Hood realizes the family is suffering medical consquences of an agricultural fungus that has been genetically modified by a company that specializes in agricultural pesticides. Though the company suspended their research on this new product, a local farmer got some of the "organic" pesticide and started using it to improve his crop yield. Hood and Rachel must not only find who has been using this pesticide, but also, what genes they inserted into the fungus in order to help save the family.