At the beginning of World War II, Lady Sarah Ashley travels from her home in England to Northern Australia to confront her husband, whom she believes is having an affair. He is in the country to oversee the selling of his enormous cattle station, Faraway Downs. Her husband sends Drover, an independent stockman, to transport her to Faraway Downs. When Lady Sarah arrives at the station, however, she finds that her husband has been murdered (allegedly by King George, an Aboriginal elder) and that cattle station manager Neil Fletcher is trying to gain control of Faraway Downs, so that Lesley 'King' Carney will have a complete cattle monopoly in the Northern Territory.
Lady Sarah is captivated by Nullah (King George's grandson) son of an Aboriginal mother and an unknown white father. When Nullah tells her that he has seen her cattle being driven onto Carney's land, Fletcher beats him. Lady Sarah fires Fletcher, deciding to try to run the cattle station herself. To save the property from Carney, she enlists the aid of Drover; together, they drive 2,000 head of cattle across hundreds of miles of the country's most unforgiving land. In the course of the journey, she falls in love with both Drover and the Australian landscape.
Lady Sarah, Nullah, and Drover live together happily at Faraway Downs for two years, while Fletcher (the actual murderer of Lady Sarah's husband and very likely the father of Nullah) kills Carney, marries his daughter, and takes over Carney's cattle empire. When the authorities send Nullah to live on Mission Island with the other half-Aboriginal children, Lady Sarah is devastated. In the meantime, she works as a radio operator in Darwin.
When the Japanese attack the island and Darwin in 1942, Lady Sarah fears that Nullah has been killed and Drover, who had quarrelled with Lady Sarah and left the station, believes Lady Sarah has been killed. Learning of Nullah's abduction to Mission Island, however, he sets out to rescue him. Lady Sarah decides to sell Faraway Downs to Fletcher and return to England. Drover and Nulla sail back into port at Darwin as Lady Sarah is about to depart, and the three are reunited. Fletcher, distraught at the death of his wife, attempts to shoot Nullah, but is speared by King George and dies.
