 In 1968, four University of Puebla employees on a mountain climbing trip were attacked and beaten, and two people were killed, by the townspeope of San Miguel de Canoa. The mob violence was apparently incited by a local priest, who had been warning the townspeope that leftists from the city would be coming to kill him. Felipe Cazals  retelling of this real-life tragedy unfolds as a faux docmuentary. There is a narrator who provides context as we are shown a landscape of rural poverty and clerical power. Cazals made the film in 1975 as a metaphor for the massacre of students in the Plaza de las Tres Culturas in the Mexico City district of Tlatelolco on October 2, 1968 a massacre the truth of which is still not known.