The film tells the story of a small train riding without its driver and the passengers locked inside. They all had originally their individual goals and destinations but now they one common target - getting out of the train or eventually stopping it. Although the train is moving very slowly, a real drama (partially very absurd) breaks out both inside and outside the train where...。欧洲某国的安妮公主到访罗马,国务烦身,但她又厌倦繁文缛节。一天晚上,身心俱疲的她偷偷来到民间欣赏夜景,巧遇报社记者乔。二人把手同游,相当快乐。公主更是到乔的家中做客并在那过夜。
不料乔无意中发现了公主的真实身份,他决定炮制一个独家新闻,于是乔和朋友、摄影师欧文一起带公主同游罗马,并且偷拍了公主的很多生活照。然而,在接下来与公主的相处中,乔不知不觉恋上了公主。为了保护公主的形象,乔只能忍痛抛弃功成名就的良机,将照片送予了公主。
安妮公主在经历了罗马一日假期后,反而体验了自己对国家的责任,毅然返回了大使馆,为了本身的责任而果断抛弃了爱情。。