The film recounts the expedition of Walter Bonatti and two of his regular climbing partners, Andrea Oggioni and Roberto Gallieni, to conquer the unclimbed Central Pillar of the Frêney. As they approach their destination, at the Fourche bivouac, the Italians encounter a party of four French climbers, led by Pierre Mazeaud. They decide to set off together: it is dawn on 10 July 1961. The climb begins and the seven mountaineers are quickly nearing their objective when, unexpectedly, a storm of snow and wind breaks out. A nightmare that traps them all on tiny ledges for four days and four nights, in the cold and without food. And this is the beginning of the tragedy.