Following a July 1940 conference in Kiel, the Abwehr (German intelligence) launched an espionage campaign against Britain involving both intelligence gathering and sabotage. The spies were sent over from Europe in various ways; some parachuted or came off a submarine. Others entered the country on false passports, or posing as refugees.[2] Public perception in Britain at that time was that the country was full of well trained German spies who were deeply integrated into society. There was widespread, as Churchill put it, "spy-mania". The truth was that between September and November 1940 fewer than twenty five agents arrived in the country; mostly of Eastern European extraction, badly trained and poorly motivated.[2] The agents were not difficult to spot - a task made still easier by the cracking of the German's Enigma encryption. MI5, with advance warning of infiltration, had no trouble picking up almost all of the spies sent to the country. Writing in 1972, John C. Masterman (who would later head the Twenty Committee) said that by 1941 MI5 "actively ran and controlled the German espionage system in [the United Kingdom]." It was not an idle boast; post-war records confirmed that none of the Abwehr agents, bar one who committed suicide, went unnoticed.[2][3] Once caught, the spies were deposited in the care of Lieutenant Colonel Robin Stephens at Camp 020 (Latchmere House, Richmond).[4][Note 1] After Stephens, a notorious and brilliant interrogator, had picked apart their life history, the agents were either spirited away (to be imprisoned or executed) or, if judged acceptable, offered the chance to turn double on the Germans.[2][5] Control of these new double agents fell to Thomas Argyll Robertson (usually called Tar, from his initials), a charismatic MI5 agent. A Scot, and something of a playboy, Robertson had some early experience with double agents; just prior to the war he had been case officer to Arthur Owens (code name Snow). Owens was an oddity, and it became apparent that he was simply playing the Germans and British against each other – to what end Robertson was unable to uncover. The experiment had not appeared to be a success, but MI5 had learned key lessons about how the Abwehr operated and how double agents might be useful.[2] Robertson, in particular, believed that turning German spies against their masters would have numerous benefits; for example determining what information the Abwehr wanted or to actively mislead them as part of a military deception. In addition, it would discourage them from sending more agents if they believed an operational network existed. Section B1A (a subordinate of B section, under Guy Liddell) was formed and Robertson was put in charge of handling the double-agent program.[6] Robertson's first agents were not a success; Giraffe (George Graf) was never really used and Gander (Kurt Goose; MI5 had a penchant for amusingly relevant code names) had been sent to Britain with a radio that could only transmit, not receive. Both were quickly decommissioned. The next two attempts involved even more farce; Gösta Caroli and Wulf Schmidt (a Danish citizen) landed, via parachute, in September 1940. The two were genuine Nazis, had trained together and were friends. Caroli was coerced into turning double in return for Schmidt's life being spared, whilst Schmidt was told that Caroli had sold him out and in anger swapped sides.[6] Caroli quickly became a problem; he attempted to strangle his MI5 handler before making an escape carrying a canoe, on a motorcycle. He vaguely planned to row to Holland, but came unstuck after falling off the bike in front of a policeman. He was eventually recaptured and judged too much trouble to be used. Schmidt was more of a success. Codenamed 'Tate', he continued to contact Germany until May 1945. However, these eccentric spies made Robertson aware that handling double agents was going to be a difficult task.[6] §Methods of operation[edit] The main form of communication that agents used with their handlers was secret writing. Letters were intercepted by the postal censorship authorities and some agents were caught by this method. Later in the war, wireless sets were provided by the Germans. Eventually transmissions purporting to be from one double agent were facilitated by transferring the operation of the set to the main headquarters of MI5 itself. On the British side, a critical aid in the fight against the Abwehr and SD was the breaking of the German ciphers. Abwehr hand ciphers were cracked early in the war, and SD hand ciphers and Abwehr Enigma ciphers followed thereafter. The signals intelligence allowed an accurate assessment of whether the double agents were really trusted by the Germans and what effect their information had. A crucial aspect of the system was the need for genuine information to be sent along with the deception material. This need caused problems on a regular basis early in the war, with those who controlled the release of information reluctant to provide even a small amount of relatively innocuous genuine material. Later in the war, as the system became a more coherent whole, genuine information was integrated into the deception system. For example, one of the agents sent genuine information about Operation Torch to the Germans. It was postmarked before the landing, but due to delays deliberately introduced by the British authorities, the information did not reach the Germans until after