一天清晨某村庄的沟壕里出现了一具僵死的女尸。在警察的调查下，死者莫娜（桑德里娜•伯奈尔 Sandrine Bonnaire 饰）的流浪岁月由此被揭开。她身背大包四处露营，与落魄的流浪汉同居在一处房子里，一起抽烟睡觉。一个老妇人的女仆尤兰德满心羡慕莫娜和流浪汉的自在状态，不满男友保罗的简单粗暴。某夜保罗入室行窃打昏流浪汉，莫娜随即不辞而别。接下来她遇到了一对放牧的夫妇，他们给了她土地和住所，期望她能努力过上平静踏实的日子。莫娜不以为然重新上路，在路上搭便车结识了以研究树木为职业的兰迪尔，兰迪尔给予了莫娜短暂的帮助后两人便分道扬镳。此后莫娜又在途中结识了剪葡萄树枝的工人阿兹，无人知晓莫娜的流浪将把她引向何处……

After the corrupt former Mayor is killed by the peasants, poor janitor Juan Vargas is appointed new Mayor of a desert town in central Mexico. Although he tries to bring the motto of the ruling party to town (modernity, peace and progress) he realizes soon that there's nothing to do against corruption... except to become corrupt. Step by step, helped by his pistol, Juan Vargas becomes the law and the worst Major in the town's history.　　　　故事讲述墨西哥农民杀死腐败的前市长后，不幸的看门人阿瓦尔加斯在墨西哥中部被任命为一个沙漠镇的新市长，他努力提倡执政党的新意识，到任不久就立下反对腐败的座右铭，但反对也开始变得腐败，一步步在他的枪手帮助下，阿瓦尔加斯成为法郎和镇上历史最恶劣的一页。