37 years ago, Patrick Gabarrou and Hervé Bouvard defied the impossible by opening the "Walker Directissime" on the north face of the Grandes Jorasses. No climber has managed to repeat this route until February 2023. Charles Dubouloz, Symon Welfringer and Clovis Paulin undertook the ascent of this face, adding an extra difficulty: making the first free ascent in winter. Welcome to the deep freeze of the unknown!