在这部杀手挽歌惊悚片中,卢瑟斯（梅拉尼·罗兰 Mélanie Laurent 饰）是一名入行已久的职业杀手，常年浸淫在充满了血腥和杀戮的生活中，卢瑟斯身心俱疲，只希望能够找到机会，金盆洗手，回归正常平静的生活之中。
为了实现自己的愿望，卢瑟斯接下了最后一个，也是最危险的一个任务，她将前往位于阿尔卑斯山上的一座城堡之中，杀掉在节日演唱会中登台表演的男高音亚里斯山大（Christopher Stills 饰）。让卢瑟斯没有想到的是，她的行踪暴露了，为了保护亚里斯山大，法国反间谍机构派出了名叫里克（科洛维斯·科尔尼拉 Clovis Cornillac 饰）的前特工，潜伏在卢瑟斯的身边，用尽一切手段，只为破坏卢瑟斯的行动。
Lucrèce is a contract killer in search of a new life. Specialized in the use of poisons and enamored with opera, she accepts a difficult, final hit in a castle in the heart of the Swiss Alps. Posing as a soprano, Lucrèce must perform on stage during the very prestigious Festival of Ermeux and slaughter one of her co-performers, British baritone Alexander Child, who recently bought a distillery in Scotland, and thus became the only obstacle to a strategic pipeline project with considerable financial ramifications. He just won a long legal battle against British Oil, who now has no other choice but to eliminate him. To complicate things, French counter-espionage learns of the hit and sends Rico, a reinstated former agent, to infiltrate the orchestra, unmask and terminate all who wish harm to Alexander Child. Rico has no information on the killer and has a lot of trouble identifying her amid a horde of suspicious characters: an obnoxious conductor, a particularly proud tenor and a strangely stressed festival director... Throughout rehearsals of Haendel's sublime Messiah, a breathless intrigue begins...and could end in a Requiem...for a killer!
一个弱爆了的侦探，一个内心不强大的女杀手。非常文艺范儿，还有许多哲理和情感流露。电影配乐很棒。影片不错。。关于杀手。.最具艺术气质杀手，剧透。最具艺术美感的杀手。胡言乱语。
