'Controversially exposes two traitors at the heart of the British establishment'

Daily Express

'An excellent read'

Daily Telegraph

'(A) vast, investigative peek through the secret barriers of British Intelligence... bewitching magic'

Mark Middles, Manchester Evening News

' Nigel West gives the operation the detective-story treatment it deserves... an excellent book'

Michael Smith, Daily Telegraph

Meredith Gardner (left), the linguistic genius at work on 'the Russian problem' at Arlingto Hall in 1946, surrounded by the women clerks who undertook much of the painstakingly difficult cryptanalysis before the introduction of computers.