Drama set in New Zealand in 1868. Samantha Morton stars as Sarah O'Brien, a woman who has grown up in a frontier garrison on the Great River, Te Awa Nui, surrounded by soldiers. Sarah fell pregnant at 16 and gave birth to a son, Boy. When Boy (Rawiri Pene) is kidnapped seven years later by his Maori grandfather, Sarah is distraught. Her only friend is Dore (Kiefer Sutherland), a broken-down soldier who doesn't have the means to help her. Lured to the ill rebel chief Te Kai Po's village by a promise that she can see her son, Sarah finds herself falling in love with Boy's uncle, Wiremu (Cliff Curtis), and slowly becomes increasingly drawn to the village way of life.