490 BC, on the eve of the Battle of Marathon. The Athenians send a messenger to Sparta (Phidippides) to ask for military help. Herodotus reports that he arrived the following day. This incredible feat is reviving in our time with SPARTATHLON. This is a 246-kilometer overpass, which has to go through 36 hours. The challenge of exceeding the limits of human endurance and historicity attracts hundreds of runners from around the world. The film follows the course of these people and the presence of many participants, who also prepare themselves, participate in this adventure. It is the effort to answer the almost metaphysical question, why all these people are suffering unimaginably, either on the road, running, or as volunteers in the control station tables, for an idea and with a unique profit, an inherent joy of glory.