Primatologist Davis (Dwayne Johnson) shares an unshakable bond with George, the extraordinarily intelligent Silverback Gorilla, who has been in his care since he was young. When a greed fuelled corporation's genetic experiment goes awry, George and other animals across the country are mutated into aggressive super-creatures, who destroy everything in their path. Davis tries to find an antidote, not only to halt a global catastrophe, but also to save the fearsome creature, who was once his friend.