The film is set in rural Québec in the 1830s. Élisabeth at the deathbed of her second husband, Jérôme Rolland, recalls her youth which is conveyed through a series of flashbacks. She was first married to Antoine, the brutish seigneur of Kamouraska, their love eventually dissolving in his mental illness and cruelties. She eventually falls in love with an American physician, Georges Nelson who later murders Antoine. At her trial for complicity in the killing, Élisabeth is acquitted and marries Jérôme to save her honor.