影片改编自萨德的代表《贾斯汀》，全称为《新贾斯汀，或美德的不幸以及姐姐朱丽埃特的故事，或恶行的走运》，十卷近四千页的罕见的情色巨著。失去双亲、寄身于修道院的姐妹贾斯汀和朱丽埃特对未来的生活产生的生活产生了分歧：贾斯廷天真、善良、纯朴，她试图在艰难的环境中保持住自己的信仰、美德和贞操，但颠倒黑白的现实让她沦为命运的玩偶，被形形色色的男人欺骗、捉弄、糟蹋；朱丽埃特自从进入妓院后便一直靠出卖肉体为职，后来又通过卑劣的手段害死了同伴，混迹到了上流社会，简直是一帆风顺、飞黄腾达。而她们姐妹的生活还能有交集还能重逢么……

Alice, a widowed Frenchwoman, goes on a vacation to Italy. Upon her return, she relates the particulars of her holiday. Within a 24-hour time frame, Alice gets on the wrong boat, winds up in Switzerland where she whiles away the hours at a casino, meets a handsome young German army deserter named Thomas, spends the night with her new acquaintance, pays his sizeable gambling debts, and helps him elude the authorities...