Two parents do what it takes to keep their children and soon to be newborn safe in a world full of creatures hunting every sound they can hear. Not a sound can be heard from the family hiding in silence, but all it takes is one noise and everything can go wrong.

Primatologist Davis Okoye shares an unshakable bond with George, the extraordinarily intelligent gorilla who has been in his care since birth. But a rogue genetic experiment gone awry transforms this gentle ape into a raging monster. As these newly created monsters 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.