影片根据发生在法国国王路易十五统治时期的真实事件改编。 18世纪60年代中期,法国路易十五在位时,一只凶残异常的巨狼一直威胁着吉瓦冈地区,而受害者多是妇女和儿童。一时间,全法国都被触目惊心的血腥杀戮震惊了,无人知道凶兽真正面貌,有人盛传是魔鬼化身。为安定民心,路易十五指派皇家骑士弗朗萨克(塞缪尔·勒·比汉 Samuel Le Bihan 饰)捕杀怪兽。在吉瓦冈逗留期间,弗朗萨克爱上了当地伯爵的女儿玛丽安(艾米莉•德奎恩饰),还与美艳动人的官妓西尔维亚(莫妮卡·贝鲁奇 Monica Bellucci 饰)有染,并结识了玛丽安的哥哥让-弗朗索瓦(文森特·卡索 Vincent Cassel 饰)。随着调查的逐渐深入,弗朗萨克从被害者遗体上发现了一颗钢牙,而一位目击者发誓宣称有人控制着巨狼。随着调查,掀起更恐怖阴谋,一场场血腥杀戮战连串发生……In 1765 something was stalking the mountains of central France. A 'beast' that pounced on humans and animals with terrible ferocity. Indeed they beast became so notorious that the King of France dispatched envoys to find out what was happening and to kill the creature. By the end, the Beast of Gevaudan had killed over 100 people, to this day, no one is entirely sure what it was, wolf? hyena? or something supernatural? Whatever it was, shepherds had the same life-expectancy as the red-suited guys in 'Star Trek'. The Beast is a popular myth in France, albeit one rooted firmly in reality; somewhat surprisingly it is little known to the outside world, and perhaps incredibly it has never been made into a movie. Until now... Based on the true story of the Beast of the Gevaudan that terrorized France in the mid-XVIIIth century, the movie aims to tell first and explain afterwards. In the first part, a special envoy of the King of France, altogether biologist, explorer and philosopher, arrives in the Gevaudan region, in the mountainous central part of France. The Beast has been attacking women and children for months and nobody has quite been able to harm it or even take a good look at it. In the second part, our hero Chevalier de Fronsac will not only have to fight the Beast, but also ignorance, bigotry and conspiracy and will rely on two women, one an aristocrat, the other a prostitute, as well as the enigmatic Mani, an Iroquois he met in New-France (Canada).