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.　　　　故事講述墨西哥農人殺死腐敗的前市長后，不幸的看門人阿瓦爾加斯在墨西哥中部被錄用為一個沙漠鎮的新市長，他盡力提倡執政黨的新意識，到任不久就立下反對腐敗的座右銘，但反對也開始變得腐敗，一步步在他的槍手幫助下，阿瓦爾加斯成為法郎和鎮上歷史最惡劣的一頁。