Pre-order the long-awaited and brain-busting sequel from the UK's finest codebreakers and puzzle-solvers at GCHQ. With their first bestselling book, The GCHQ Puzzle Book, the UK's intelligence and sec
** WINNER OF 'STOCKING FILLER OF THE YEAR AWARD' GUARDIAN ** Pit your wits against the people who cracked Enigma in the official puzzle book from Britain's secretive intelligence organisation, GCHQ. '
