S1, E2: The 20,000 islands of the South Pacific may be the most isolated in the world, but every one of them has been colonised. This is the story of the ultimate castaways - from salt water crocodiles and giant eels to crested iguanas and weird frogs - who succeeded against all odds to reach islands thousands of miles apart. The voyages of the South Pacific's first people - the Polynesians - were no less remarkable. These journeys were undoubtedly the greatest acts of navigation ever undertaken, and they changed the nature of the South Pacific forever.