He had strong communication and organizational skills, and as the head of the Musician network he and fellow SOE agents and members of the French Resistance organized very productive sabotage missions. Operating from a base in Saint-Quentin in the northern Aisne "département", Biéler's twenty-five teams, scattered over different areas of northern France, succeeded in damaging or destroying German gasoline storage tanks, rail lines, bridges, canal locks, and the electric tractors used to tow barges on the shipping waterways. Their repeated efforts hampered the movement of enemy arms and troops but the most important job for Biéler would eventually be the preparations for D-Day.