In the 1930s, the vogue for mountaineering brought to Savoie a cosmopolitan, worldly and athletic crowd eager to conquer the peaks. Jean Servettaz, a Chamonix guide, decided to prepare his son to become a hotelier to keep him away from the objective risks of the high mountains and to spare him the harsh existence of mountain dwellers. That didn't stop Pierre from training and being a fine climber. So he is one of the volunteers of the roped party who must lower the body of his father killed by lightning during a storm on his return from a race in the Drus. Snow and ice make the expedition almost impossible. For having wanted to force a passage anyway, Pierre falls. He will only get up from his hospital bed more determined not to sink into the life of a man of the plains, he will be a guide like his father. Bianca, the daughter of the rich Milanese responsible for the death of his father, comes see him in the hospital...

The accident of the mountain guide Joseph, the patriarch of Servettaz, marked the spirits. His son Zian decides to take up the torch. Married to Bianca, the daughter of the wealthy Milanese industrialist who accompanied her father in the ascent of the Drus, Zian lives his great love story, a three-way love story, the mountain always remaining the most demanding mistress. Tired of the agonizing expectations and loneliness during her husband's climbs, Bianca returns to Italy. Zian will join her, but the society life of the Milanese bourgeoisie is far from his values ​​and he returns to his mountains, to Chamonix. During a chamois hunting trip in the mountains, Zian falls into a crevasse. Bianca, alerted by a presentiment, returns to the one she loves above all...