Set in the 1850s, Mistress Madeleine unfolds against the backdrop of the Hudson's Bay Company's monopoly of the fur trade. In protest, some Métis are trading with the Americans. Madeleine, the Métis common-law wife of a Hudson's Bay Company clerk, is torn between loyalty to her husband and loyalty to her brother, a freetrader. Even more shattering, a change in company policy destroys Madeleine's happy and secure life, forcing her to re-evaluate her identity.