Cast & Crew
Municipality of San Martín del Rey Aurelio, Principality of Asturias (north to Spain). Daniel is an Argentinian descendant of mine-worker Asturian immigrants who works as office technician in the Pozo Sotón, one of the best known mining wells of all Asturias located between the towns of Sotrondrio and El Entrego. With the business of extract coal close to its end Crespo and Sánchez, two CEOs of the mining work company, send Daniel to his first field work to explore a passage of the fourth underground floor, so-so 1,500 meters (0.93 miles) below the surface, in the hope to find a new vein of coal to extract it. But once there a collapse of the mine by a firedamp explosion causes a crumble in the roof of the passage, getting trapped five miner-workers: José, an aged miner with four decades of experience at the edge to be retired; Soto, another veteran mine-worker; María, a young woman who is an explosives technician; Radek, a Russian miner severally hurt by the crumble; and finally the own Daniel. At the same time that outside the mine Daniel's grandfather Carlos returns to his Asturias natal from Argentina looking for recover his great-son at any cost, and that the firemen of the Brigada de Salvamento Minero (Miner Saving Brigade) Luis, Fran and Félix are determined to save their friend Daniel and the others, inside the situation worsens: with no food and barely water to still alive, the eternal dark and isolation of the place forces Daniel by means of a series of delusions and hallucinations to face his past and his youth days, when met his ex wife Marga and turned in father of his little son also named Daniel, while he talks with María, José and Soto in an desperate attempt to keep his mental sanity. With the pass of the days, the physical and mental conditions of Daniel and the others united to the absence of a healthy environment go the group to take a decision: wait for an each more improbable rescue, or dig a tunnel in the collapsed ground to create a way to be free. But when the days turn in weeks, Daniel and company must to struggle with a terrible reality: die in the passage, or take an extreme measure as their last hope to survive, despite it too could be kill them.