Prends ton passe-montagne, on va à la plage: A group of friends—Julien, Sophie, Gaspard, Caroline, and Victor—are planning a major mountaineering trip to climb the Tibetan peaks in July, under the supervision of their friend Sébastien, a medical student. Shortly before their departure, Sébastien breaks his leg and has to give up a summer job as an instructor at a thalassotherapy center in Le Touquet, which was meant to finance his studies. Victor then offers to replace him, and the others decide to go to Tibet anyway.