Pit your wits against the people who cracked Enigma in the official puzzle book from Britain's secretive intelligence organisation, GCHQ. GCHQ is a top-secret intelligence and security agency which recruits some of the very brightest minds. Over the years, their code breakers have helped keep our country safe, from the Bletchley Park breakthroughs of WWII to the modern-day threat of cyberattack. So it comes as no surprise that, even in their time off, the staff at GCHQ love a good puzzle.
