While out on a picnic in the Australian outback with his teenage daughter (Jenny Agutter) and young son (Lucien John), a man goes insane and kills himself. The girl takes her brother into the outback in order that he doesn't see their father's dead body. There they meet a young Aborigine (David Gumpilil) who is on walkabout - a rites of passage ritual whereby he must survive in the wilderness for several weeks. He finds food and water for the siblings, and develops a form of communication with the young boy despite being unable to speak English. The girl, however, rebuffs the mating dance which the Aborigine performs in her honour.