In 1906, two years after the appearance of her best-known novel, The Imperialist, Duncan published its darker twin, an Anglo-Indian novel which returns to political themes but with a deeper and more clinical irony than in her previous work. Set in Authority is about illusions: the imperial illusions of those who rule and are ruled; the illusions of families about their members; the illusions of men and women about each other. The setting moves between the political drawing rooms of London and the English station at Pilaghur in the province of Ghoom, where the murder of a native by an English soldier changes the lives of a cast of ruthlessly observed characters.

Duncan, who grew up in Ontario, led a remarkably varied life, working as a political correspondent (writing for the Washington Post, the Toronto Globe and the Montreal Star) and living in India for over twenty years. She is increasingly being regarded as deserving of a place among the first rank of nineteenth- and early twentieth-century novelists; the re-publication of Set in Authority will do nothing to dispel that view.