The Chihuahuan Desert is considered one of the arid regions with the greatest wealth of species in the world. At the current rate of loss, it is estimated that by 2025, its natural grasslands will disappear in the state of Chihuahua, Mexico alone. “Ad memoriam rei perpetuam”, records for perpetuity through the lens of its director, Mauricio De la Maza-Benignos, the acts and events that are transforming the natural grassland ecosystem into another corporality, “the human that circulates, divides and blocks”. The film uncovers, with the voice of acclaimed poet Claudia Luna Fuentes, the historical conflict between grassland ecosystems, freshwater, human nature and biodiversity, that is pushing this biome to its extinction. Moreover, the film addresses using solemn poetry, the absurd, satire, beauty and hope, through interviews with the various actors of the conflict, two dimensions of life, nature and human, since the latter usually "decides over price, and not value the fate of what is not possible to price".