To find good drop zones to supply the Maquis with arms and sabotage equipment, a mission composed of Richard Henry Heslop from the Special Operations Executive and Captain Rosenthal from the Free French Forces was sent from London.

Captain Rosenthal, the Free French representative, persuaded the other staff members to regroup the majority of maquisards on the Glières Plateau, to establish a base to attack the Germans and carry out sabotage.

One of the patrols, from a Gebirgsjäger (mountain troops) platoon, made an attack on the main exit from the plateau and captured an advance post in the rear.

Sustaining the attack from about fifty German soldiers, eighteen maquisards fought and resisted into the night but were outnumbered and overwhelmed, though most of them escaped under cover of darkness.

The region of Savoie had suffered badly, but the defeat was turned into a propaganda victory and gave a boost to the French Resistance in the spring of 1944.