Given the code name "Marguerite", Baissac and Andrée Borrel, became the first women agents to be was parachuted into France on 24th September 1942. They landed in the village of Boisrenard close to the town of Mer.
After staying with the French Resistance for a couple of days Baissac moved to Poiters whereas Borrel went to Paris to join the new Prosper Network. Over the next few months Baissac acted as liaison officer between the Prosper, Scientist and Bricklayer networks.
As she did not have a wireless she had to travel to Paris to send and receive messages and collect funds, or to Bordeaux where Claude de Baissac was building up the large circuit, organising sabotage and providing reports on submarines and shipping.
Baissac was dropped back into France in April 1944, to work with the Pimento Circuit run by the SOE agent Anthony Brooks. However, she came into conflict with the group (she thought they were militant socialists with political aims) and joined her brother Claude de Baissac, who had gone to Normandy to reconnoitre large landing grounds that could be held for 48 hours while airborne troops established themselves.
A British army officer later claimed: The part she played in aiding the Maquis and the British underground movement in France cannot be too highly stressed and did much to facilitate the Maquis preparations and resistance prior to the American breakthrough in Mayenne. According to her Special Operations Executive file: She was the inspiration of groups on the Orne and by her initiative caused heavy losses to the Germans with tyre bursters on the roads near St Aubin-le-Desert, St Mars, and as far as Laval, Le Mans and Rennes. She also took part in several armed attacks on enemy columns."
Baissac was awarded the MBE in September, 1945. After the war she married Henri Villameur, an artist and interior decorator living in Marseilles.
Lise de Baissac died aged 98 in Marseilles on 28th March, 2004.