In May 1940 Francis Suttill was commissioned into the East Surrey regiment of the British Army. He was later recruited by the SOE, and after being trained during the summer of 1942, Suttill was chosen to create a new resistance network in northern France, based in Paris, with the operational name Physician. His code name was Prosper and his assumed identity was Francois Desprees. The circuit of agents grew fast until June 1943, when the Gestapo discovered letters, instructions, crystal sets and addresses in a car and false ID papers in an apartment. Over the next three months, more then eighty agents died or were killed, mostly in concentration camps. Major Suttill DSO would be killed in Sachsenhausen in May 1945. Rumours of betrayal by MI6, even of the involvement of Winston Churchill, have abounded ever since. For the first time, Major Suttill's son tells the whole story of the tragedy basing his meticulous research on primary sources.