The small Utah town of Fryeburg is known for Valley Forest, the forest preserve known as a haven for hikers, campers, and hunters. A prolonged, intensive heat spell has awakened something in Valley Forest that has transformed what once was natural into something dangerously unnatural. When Juliette Marques, whose house abuts the forest, dies suddenly and her family comes to Fryeburg for her funeral, it is discovered that her death was also not natural. Her niece, Olivia Ferguson, is insistent that there is something amiss in the forest that contributed to Juliette's death, an opinion that raises the ire of the people of Fryeburg. With her cousins Loren Brooks and David Brooks, Olivia endeavors to understand what is happening in Valley Forest and why the town's residents are suddenly displaying bizarre behavior. Animals living in the forest have suddenly turned aggressive, and an abundance of certain weeds growing throughout the town that display abnormal characteristics leads Olivia to suspect that the extended heat wave and something hidden within Valley Forest is causing plant and animal life to behave in ways never observed before. When the town authorities grow insistent that she leave Fryeburg and she finds herself the victim of acts of vandalism, Olivia becomes convinced that Fryeburg is hiding knowledge about the source of the dangers in Valley Forest that are claiming lives and posing an increasing threat to the town and, she fears, possibly all of Utah, something reinforced by the involvement of a major chemical company with close ties to the town. With her safety on the line, she fights to uncover the truth before more people die and a decades-long conspiracy is permitted to continue.