Batey was recruited by Welchman in 1940 and worked in
Hut Six, which was responsible for breaking the German Army and Air Force Enigma ciphers. While there he met fellow code-breaker, Mavis Lever, who worked with
Dilly Knox's research section, reconstructing new Enigma machines as they were introduced. Batey assisted Lever in reconstructing one of the rotors of a new Italian Enigma machine. They married in 1942. In 1942, Batey wished for a more physically active role in the war as a pilot in the
RAF, but was rejected due to his knowledge of
Ultra and the risk of getting captured. Instead, he persuaded the authorities to allow him to train as a pilot with the
Fleet Air Arm for the defence of
Canadian waters. However, he was recalled to work in a newly created section known as ISK, standing for Intelligence Services (Knox) alongside his wife.
Dilly Knox had just reconstructed the main Enigma cipher machine used by the Abwehr, German military intelligence, and the ISK section was to play a key role in the
Double Cross System which "turned" German agents sent to Britain and elsewhere in the world and used them to feed false intelligence back to the Germans. During 1943, Batey broke the Enigma ciphers of the
Sicherheitsdienst, the Nazi party's intelligence service, along with the cipher used by
Italian military
attachés in
Berlin. ==Post war work==