Primatologist Davis Okoye shares an unshakable bond with George, the extraordinarily intelligent, silverback gorilla who has been in his care since birth. But a rogue genetic experiment gone awry mutates this gentle ape into a raging creature of enormous size. To make matters worse, it’s soon discovered there are other similarly altered animals. As these newly created alpha predators tear across North America, destroying everything in their path, Okoye teams with a discredited genetic engineer to secure an antidote, fighting his way through an ever-changing battlefield, not only to halt a global catastrophe but to save the fearsome creature that was once his friend.

In the mid-1980s, the U.S. is poised on the brink of nuclear war. This shadow looms over the residents of a small town in Kansas as they continue their daily lives. Dr. Russell Oakes maintains his busy schedule at the hospital, Denise Dahlberg prepares for her upcoming wedding, and Stephen Klein is deep in his graduate studies. When the unthinkable happens and the bombs come down, the town's residents are thrust into the horrors of nuclear winter.

When military experiments go haywire and trigger an atomic bomb, the consequences are of epic proportions. A monster arrives in the midst of the nuclear fallout, and Japan's defenses are helpless against it. Mankind's only savior is an irradiated water goblin from Japanese folklore called the "Death Kappa." The two rival monsters must go head-to-head in the ultimate battle between good and evil!