The GCHQ Puzzle BookThe GCHQ Puzzle Book is a unique collection of puzzles from the British intelligence organisation, GCHQ. GCHQ is a top secret intelligence and security agency, known for recruiting some of the very brightest minds. Over the years, their codebreakers have played a vital role in keeping the country safe, from the Bletchley Park breakthroughs during WWII to countering modern day cyberattacks. It's no surprise that, even during their leisure time, the