 A group of explorers from the British Cryptozoological Society (and two television cameramen) goes on an expedition into the Congo in search of a cryptid—the so-called Mokele-mbembe—which is believed to be a Plesiosaur.The explorers' leader, Jonathan, discovers during the helicopter flight, that his son Luke sneaked into the chopper as a stowaway.Shortly after that, a flock of large flying reptiles appears next to the helicopter, causing the helicopter to crash.