故事发生在二十世纪初的墨西哥革命中。一辆长途马车里，高贵的先生女士们对一位沉默寡言的农民大放厥词，然而突然农民摇身一变，显出家庭式匪帮头目胡安（Rod Steiger 饰）的真面目。胡安打劫后路遇爱尔兰革命军爆破专家约翰（James Coburn 饰），后者的爆破能力令抢劫梅萨维德银行如探囊取物，于是胡安苦苦尾随，不经意间却卷入了配合维拉革命军的梅萨维德暴动。胡安如愿与约翰搭档洗劫银行，但他所有的收获却是解放150名政治犯人。 　　政府军上校刚特率军镇压革命，胡安与革命队伍付出了惨痛的代价。在逆境中，约翰与胡安产生了真正的革命情谊，二人在前往美国的路上折返阻击刚特上校，当约翰中弹之时，这位老战士看到了昔日在爱尔兰的温馨场景……本片获1972年意大利大卫奖最佳导演奖。

The film is a dramatic re-enactment of real-life events that took place in 1968 in the small village of San Miguel Canoa in Puebla, México. There a group of five young employees of the Autonomous University of Puebla intended to spend the night en route to a hike up La Malinche. The group was viciously set upon by villagers who had been manipulated by a local right-wing priest to believe them to be Communist revolutionaries and deserved lynching. 　　The film is shot in a documentary style and examines the pervasive atmosphere of repression in the country following wide-spread protests over the government's spending on the 1968 Summer Olympics, eventually leading to a massacre of hundreds of protestors in Mexico City.