In the late Victorian period, two young cousins, 9-year-old Richard (Glenn Kohan as Young Richard) and 7-year-old Emmeline Lestrange (Elva Josephson as Young Emmeline), and a galley cook, Paddy Button (Leo McKern), survive a shipwreck in the South Pacific and reach a lush tropical island. Paddy cares for the children and forbids them by "Law" from going to the other side of the island, as he had found remains from bloody human sacrifices on an altar there. He also warns them against eating a deadly scarlet berry. Paddy later dies after a drunken binge. Now alone, the children go to another part of the island and rebuild their home.