In the tunnel on the blue path, just after the boulder marked "D", en 20-30m above Haute Précision. Low sitstart without crash-pad at the beginning of the tunnel just left of the small boulder on the ground with the two hands in the jug, climb the roof-arete on the right, take the bidoigt of the start of Non aux Gaz de Schiste raccourci and exit in that one at the orange arrow.