Déricourt was the organiser (leader) of the Farrier network (or circuit) in France. Déricourt's job with SOE was air movements officer. He found clandestine landing fields for RAF airplanes and organized receptions for the arrival and departure of flights to convey SOE agents back and forth from England to France. Déricourt also acted as a postman, collecting mail and messages from SOE agents for transmittal to SOE headquarters in London with the airplane pilots. He was highly successful at the job and came into contact with many agents of Prosper, the SOE's largest and most important network in France.