This episode investigates remote islands and their inhabitants. Some islands are tips of volcanoes; others are coral atolls. Those that colonise them transform into new species with comparative speed. Attenborough visits Aldabra in the Indian Ocean, which is 400 kilometres from the African coast. It has a vast population of sooty terns, which enjoy a degree of protection from predators that is unavailable on the mainland. The giant tortoise has also proliferated, despite the inhospitable nature of the landscape. Many island birds become flightless, including the Aldabran rail and the extinct dodo of Mauritius. Living in such isolation seems to allow some species to outgrow their mainland cousins, and Attenborough observes a group of feeding Komodo dragons at close quarters. The volcanic islands of Hawaii have become rich in vegetation and therefore a multitude of colonists: for example, there are at least 800 species of drosophila that are unique to the area. Polynesians reached Hawaii well over a thousand years ago, and their sea-going culture enabled them to reach many Pacific islands, including Easter Island, where they carved the Moai, and New Zealand: the ancestors of the Maori. Attenborough highlights the kakapo as a species that was hunted to near-extinction. It is a facet of animal island dwellers that they have developed no means of self-defence, since their only predators are those that have been introduced by humans.