The Martin family is shopping in a department store. Tiennot is responsible for looking after his little brother, Bébert, but he prefers to chase girls. On the train home, Tiennot leaves Bébert alone. On arrival, Bébert has disappeared. The Martin family sets out to find him.

Less than two years after his serious road accident, Eric Escoffier brought together the "Turbo" team (Frédéric Ancey, Michel Fauquet, Christine Janin and Stéphane Schaffter) with whom he will attempt to climb Everest without oxygen and without prior acclimatization in the Himalayas, the project being to complete the Paris-Everest-Paris loop in two weeks. It is also a medical experiment: the athletes spend a week at Mont Blanc, at the Vallot observatory between 4000 and 4800m, then a week in a hypobaric chamber in Grenoble. Doctors (Dr. Richalet, Herry and Bittel) perform tests throughout this training, which will learn about how the body acclimatizes to altitude and allow applications in the management of mountain-related illnesses . On September 2, 1989, they arrived at Everest base camp in China. They attempted the ascent via the North Col but could not carry out their project, prevented by bad weather.

In 1983, three climbers became the first French people to reach the summit of Everest. Among them were expedition leader Pierre Mazeaud and a promising 25-year-old climber, Jean Afanassieff. Twenty years later, the two legends, accompanied by mountain guide Michel Pellé, retrace the steps of their exploit and make the trek from Kathmandu to the foot of the roof of the world. This is an opportunity to retrace the history of the successive assaults on Everest and to assess the current situation of a mountain that has become a victim of its own success: while Sherpas have been able to take advantage of Western enthusiasm and thus enrich themselves and equip the summit to make it more accessible, the site's attendance poses numerous problems, both human and ecological.