In contact with rural communities in the heart of the Andes, the two explorers Geoffroy and Loïc de La Tullaye want to understand the difficulties facing Peru and Bolivia, in the grip of major economic and societal changes. The Andes mountain range is punctuated, on its intertropical part, by glaciers. True climatic markers, these kings of the mountain pastures have been the object of a cult by the Andean populations for thousands of years. On the verge of disappearing from the mountains, these guardians of time reveal their ultimate secrets. Aside from scientific reports, the local populations have their version of the facts.