一个小组学生乘公共汽车去一个小镇, 为了完成专业实践。 所有人都是朋友, 并且他们决定唱一些现代歌曲, 使其它乘客设法睡觉。 乘客的当中一个生气和呼喊"中止了他们。 但当他们到达镇子, 知道事件以后, 大家对待他们好象罪犯一样。

A rumor reaches a small town, San Garabato, that a government infiltrator will arrive to check the conditions of the community. Quickly, the municipal president, Don Perpetuo del Rosal, orders the imprisonment of those who might give a bad image. An indigenous man named Calzonzin arrives in town, pursued by two men. He is quickly taken as the infiltrated inspector, and protected by all the local authorities.

The legendary life of Mexican singer Lucha Reyes is the basis of this fictionalized biography ( or as director Arturo Ripstein puts it "an imaginary biography"). Lucha Reyes was an unconventional, and sexually liberated woman, most famous for her "cancion ranchera" style singing. Her story begins in 1939, where at 33 she still lived at home with her mother, Dona Victora, the madame of a renowned Mexico City whorehouse. Lucha marries the liberal Pedro Calderon and then buys a beggar's daughter. She becomes the mother to this child, Luzma. Lucha craves lasting love like junkies crave heroin. But for her loyal daughter, she never finds it and in the end no one can help her.