Off the western coast of Papua New Guinea lies a mysterious archipelago: Raja Ampat. It is home to a few island people and to rare tree-kangaroos and colourful birds of paradise. Raja Ampat - which means "Realm of the Four Kings" - houses types of fish not to be found anywhere else in the world. These endemic species include the walking shark, a small creature that uses its fins to move along the sea floor. Following its discovery in 2006, the walking shark made Raja Ampat the focus of attention from the international media. Rolf Möltgen set out on an adventure: for four months, he and his camera accompanied marine biologists, nature conservationists and fishermen through the island world of Raja Ampat.