A turtle paddles off the coast of Borneo, in the warm waters south-west of Asia: along the coral reef lives the richest variety of life forms in the entire ocean. Many inhabitants of the reef live their whole life in the space of a few centimetres. Others are visitors from far away, voyagers who have travelled thousands of kilometres. These animals have faced many dangers to come here, guided by the memory of a time when they lived on dry land. We witness an extraordinary spectacle,  just  8  metres  down:  it   seems as    though  a  mysterious  rite  is  being performed. The protagonist is the oldest reptile living under the sea. Marine turtles swam in the oceans of prehistory. Luckily, it seems they intend to survive for a long time to come in the ocean!