The tuatara is the sole survivor of a reptile species that has been extinct for 135 million years. This nocturnal creature which once lived world-wide, is now confined to a few off-shore islands in New Zealand. Tuataras grow up to 60 cm (two feet) in length, live to 150 years of age and have survived virtually unchanged since primeval times. The film is set on tiny Stephen's Island, a wildlife sanctuary which is a home for 100,000 of these unique reptiles.