Sharpen your mind to beat the smartest brains in Britain with the original official GCHQ puzzle book
Would GCHQ recruit you? Pit your wits against the people who cracked Enigma in the official puzzl……続きを見る
Train your brain with these fiendishly difficult puzzles, the perfect companion for anyone wanting to keep their mind busy
'Fiendishly tricky' Daily Mail
With their first bestselling book, The GCHQ ……続きを見る
