This documentary is a reconstruction, based on archive footage, testimonies, and filmed reconstructions, of the Vincendon / Henry tragedy. December 1956: Jean Vincendon and François Henry, two young mountaineers, aspire to join the High Mountain Group. Lacking experience, they set out to climb Mont Blanc via the Brenva spur in the middle of winter. The weather conditions deteriorated, and they decided to give up before meeting Walter Bonatti and Sylvano Gheser. They then decided to continue the climb and set off in two different roped parties. Bonatti decided to take refuge at the Vallot refuge higher up, rather than descend. The two young mountaineers, overcome by the poor weather conditions and fatigue, remained stuck for several days at 4,000 meters. What followed was a completely disorganized rescue operation that became, for more than ten days, a spectacle for all of France and a national tragedy.
| Actor | Role |
|---|---|
 Jean VincendonSelf (archive footage) | Self (archive footage) |
 François HenrySelf (archive footage) | Self (archive footage) |
 Claude DufourmantelleSelf | Self |
 Lionel TerraySelf (archive footage) | Self (archive footage) |
 Walter BonattiSelf (archive footage) | Self (archive footage) |
| PPierre CouttetSelf | Self |
| GGilbert ChappazSelf | Self |
| JJacques PetetinSelf | Self |
| JJean BrissaudSelf | Self |
| HHonoré BonnetSelf | Self |
| JJean MinsterSelf | Self |
| LLouis PiralySelf (archive footage) | Self (archive footage) |
| OOlivier ParisetNarrator | Narrator |
 Jean-Yves BertelootNarrator | Narrator |