The purpose of SOE was to conduct espionage, sabotage, and reconnaissance in countries occupied by the Axis powers, especially Nazi Germany.

Trotobas's first mission to France in September 1941 ended with his arrest by Vichy police and imprisonment for several months until he and other SOE agents escaped in July 1942.

He led many successful sabotage operations before being betrayed by a member of his network and killed in a gun battle with the German military police.

He headed a "powerful circuit of more than 800 resisters of the German occupation, with an escape line, an intelligence gathering service, and numerous parachute reception grounds.

During his training he was generally praised by his instructors; his "guts and determination,"[3] leadership qualities, and military experience were cited, although he was also considered "impetuous" and impatient.

[4] Trotobas parachuted into France on the night of 6/7 September 1941 as part of a group of six SOE agents who scattered after landing near Tendu in Indre Department.

At this early stage in the history of SOE, his primary task was exploratory, looking for opportunities to create, organize, and supply with arms and equipment the fledgling French Resistance.

Trotobas led the way, carrying a strip of carpet to lay down on the ground and trailing a ball of string behind him for signaling—-one twitch for okay, three for danger to the prisoners who followed him, one by one.

[8] All eleven SOE agents escaped and, after hiding in the woods while an intense manhunt took place, made their way in small groups to meet up with Hall in Lyon by 11 August.

Unlike many SOE agents whose priority at that time in the war was to gather intelligence and arm and organize resistance groups, Trotobas's job was explicitly sabotage.

Trotobas established his headquarters, which became a bee-hive of activity, in a back room of the Aquarium Cafe owned by Madeleine Thirou near the center of Lille.

Over the following months, his growing army of supporters began to carry out 15 to 20 derailments per week, creating delays is the supply of military goods to the large German forces in the Lille region.

His largest sabotage operation was the night of 27/28 June 1943 when Trotobas, with a forged Gestapo identification card, and 20 men dressed in gendarmerie uniforms talked their way into the locomotive works in Lille and destroyed four million litres of oil and damaged 22 transformers.

[23] In London the Ministry of Economic Warfare and the Air Ministry were skeptical of Trotobas's claim of a successful operation and rather than offer congratulations requested photographs of the bombed factory, no easy task as the Germans were now "rounding up railway workers, racing through working class districts in their squad cars, and smashing in the doors to drag out wives and children as hostages."

Trotobas gained access to the factory with a forged pass identifying him as an official of an insurance agency, persuaded the Germans investigating the ruins to help him take photographs, and sent the photos to London.

The RAF was reluctant to undertake supply missions near Lille due to the heavy volume of anti-aircraft fire that greeted its aircraft.

The distant sites of the air drops meant that the Farmer circuit had to transport supplies by road to its scattered groups, a hazardous undertaking.

The wireless operator assigned to Farmer, Arthur Staggs, proved to be of little use due to a defective radio and, until it was replaced, had to rely on neighbouring circuits to make contact with London and receive the vital messages needed to enable parachute drops of explosives and supplies.

With the Germans now aware of him, Trotobas changed his appearance by dying his blond hair black, shaving his mustache, and wearing the uniform of a pro-German paramilitary organization, the Groupe mobile de réserve.

In early November 1944, the Farmer Network carried out four derailments of trains in five days leaving the line "absolutely littered" with damaged railway equipment.

[36] On 24 November Denise Gilman was also ill (possibly pregnant) and Trotobas stayed with her in an apartment that he feared might not be safe, but with the German crackdown, the pair seemed to have run out of hideouts in Lille.

SOE's guidance to captured agents who were being tortured was to try to remain silent for at least 48 hours to allow their colleagues and associates time to change locations and cover their tracks.

[38][39] A later court of inquiry in England concluded that Reeve was not guilty of deliberate disloyalty, "but it cannot be said in his favour that he showed as much consistency and firmness of character when being maltreated by the Germans as has been shown by a great many other agents in similar circumstances.

Pierre Séailles become the leader and a report to SOE said that "the threads of the organization....remain unbroken and ready for the resumption of activity."