Kammala jumla mai zuwa: A Yaƙin Duniya na II Nigel de Grey an sanya shi zuwa "Gwamnati Code da Cypher School" (GC & CS) a Bletchley Park, inda ya mai da hankali kan zirga-zirgar Jamusawa da aka ɓoye akan na'urar ɓoye Enigma. A watan Satumbar 1941 ya ba da rahoto ga Firayim Minista tare da farkon nassoshi daga hukumomin Jamus zuwa ga rundunonin 'yan sanda na kansu
tsarin daidaita ƙauyuka da kuma kawar da mutanensu. Wata alama ta yi alfahari da kashe mutane 30,000 "a tsakiyar yankin". Bayan gargaɗin da aka yi a cikin jawabin da Churchill ya yi wa majalisa, wata sanarwa ta Jamus a watan Oktoba 1941 ta yi gargadin cewa kada a sake yin magana game da "ayyukan da ke da mahimmanci" a tashoshin mara waya.