Steve Austin and Dr. Rudy Wells fly to Dove Island, a desolate research facility, where scientist Cheryl Osborne, has been working in total solitude for two years. Osborne has been trying to perfect a drug which might turn an average person into a genius, using a chimp as her subject. But when Steve and Rudy reach the island, Cheryl is missing and her laboratory has been destroyed. As the two men search through the rubble, Rudy is attacked and bitten by a powerful, crazed chimp, which then flees into the jungle. Within hours, Rudy becomes a psychotic paranoid superman, who believes Steve and Cheryl are plotting against him.