蕾切尔(艾米莉·布朗特 Emily Blunt 饰)有着严重的酒精依赖症,为此,丈夫汤姆(贾斯汀·塞洛克斯 Justin Theroux 饰)离开了她,和名为安娜(丽贝卡·弗格森 Rebecca Ferguson 饰)结婚,没过多久,两人有了爱情的结晶,这令无法生育的蕾切尔痛彻心扉。 每天,蕾切尔都会搭乘火车进城,车窗外一闪而过的画面中,美丽的女子梅根(海莉·贝内特 Haley Bennett 饰)的身影吸引了蕾切尔的注意。年轻美丽的梅根住在舒适的大宅之中,有着英俊的丈夫斯科特(卢克·伊万斯 Luke Evans 饰),两人恩爱有加,她拥有着蕾切尔渴望但无法拥有的一切。然而某日,蕾切尔震惊的发现梅根竟然在和一名陌生男子偷情,而没过多久,报纸上便刊登出了梅根失踪的新闻。The Girl on the Train is the story of Rachel Watson's life post-divorce. Every day, she takes the train in to work in New York, and every day the train passes by her old house. The house she lived in with her husband, who still lives there, with his new wife and child. As she attempts to not focus on her pain, she starts watching a couple who live a few houses down -- Megan and Scott Hipwell. She creates a wonderful dream life for them in her head, about how they are a perfect happy family. And then one day, as the train passes, she sees something shocking, filling her with rage. The next day, she wakes up with a horrible hangover, various wounds and bruises, and no memory of the night before. She has only a feeling: something bad happened. Then come the TV reports: Megan Hipwell is missing. Rachel becomes invested in the case and trying to find out what happened to Megan, where she is, and what exactly she herself was up to that same night Megan went missing.