Harry Peulevé undertook three missions to France and eventually formed a clandestine circuit called Author where he armed and trained more than 4000 members of the resistance. He was aware of being on the Gestapo wanted list but turned down an opportunity to be extracted from France by the RAF Special Duties Squadron. Peulevé and several members of the local resistance were later arrested at a safehouse and eventually taken to the Gestapo headquarters in Paris where they were separated before being interrogated.
Peulevé was tortured for several days but refused to answer their questions and was transferred to a solitary confinement cell at Fresnes Prison. During an escape attempt he was shot in the leg and after being refused medical treatment was forced to remove the bullet by digging it out with a dirty prison spoon whilst hoping the wound would not become infected. He was later deported to a concentration camp and after eleven agents were executed and knowing he could be next he swapped his identity with a French prisoner named Marcel Seigneur who had died from Typhus. In early 1945 Peulevé, now known to the SS guards as Marcel Seigneur, was transferred to a labour detail where he was forced to dig anti-tank ditches near the River Elbe and after advancing American forces reached Magdenburg he managed to escape.
Several hours later he was stopped by two SS soldiers but managed to convince them he was a French collaborator trying to avoid the advancing Americans and then warned them to remove their tunics and insignias because the Americans were shooting members of the SS. As they began to undress Peulevé grabbed one of their pistols and later handed them over to soldiers of the 83rd US Infantry Division. After being debriefed he returned to England and landed at Croydon Airport on 18 April 1945.