Barely surviving her first expedition to the primordial island, Dr. Tracey Moran joins a mission to rescue those left behind. Better armed and prepared, the new expedition finds the lost world in chaos. Dr. Peter Albanese, having accidentally awoken an extinct reptilian race, must now protect the friendly indigenous tribe from their relentless attacks. A sympathetic reptilian figure reveals some of the island's history and sets Peter on a quest to awaken an extinct simian race and restore balance. All the while, an evil entity bent on escaping the island stalks Peter and the other survivors. Reunited, Tracey and Peter must contend with hungry dinosaurs, mythical forces, and corporate greed to restore balance and escape with their lives.