In 1863, during the American Civil War, Adèle Hugo, second daughter of the famous writer Victor Hugo, joined her parents in exile in Guernsey. There, she encountered an English officer who later departed for Canada, seemingly indifferent to her. In response, Adèle sought to regain his affection using any means possible. In her diaries, she wrote about a passion that consumed her and took her to the brink of delirium. The film is inspired by her real-life diaries.