GCHQ has released its Christmas Challenge for the second year running, with Gloucestershire residents invited to see if they can solve a series of puzzles devised by its in-house masterminds.
The challenge is designed for schools and colleges and features on the director's annual Christmas card, but the Cheltenham-based intelligence agency is encouraging members of the public to have a go at cracking it, too.
In the 2022 challenge, there are seven 'fiendish' puzzles to solve, inspired by GCHQ's seven core disciplines from the recently published Puzzles for Spies book: languages, engineering, codebreaking, analysis, maths, coding and cyber security.
However, it's not as simple as solving all seven puzzles. Once you've got all the answers, you'll need to use the design on the front of the Christmas card to assemble them, in order to form three what3words locations. Challengers then need to put the three place names together to reveal the final answer.
The puzzles test things like lateral thinking, ingenuity and perseverance - all key skills individuals need to work at the agency.
GCHQ's director, Jeremy Fleming, said: 'From breaking Enigma to harnessing the latest cutting edge technology, our brilliant people have worked together throughout our history to help keep the country safe.
'This year's GCHQ Christmas Card challenge gives an insight into the skills we need every day as part of our mission - from languages to coding.
'But skills alone won't be enough to crack this one. Puzzlers need to combine a mix of minds to solve the seemingly impossible.'
Keen puzzlers can download a PDF version of the Christmas Challenge card from GCHQ's website, with challengers encouraged to share their progress on social media tagging GCHQ and using the hashtag #GCHQChristmasChallenge - with the promise of a hint or two if they get stuck.
However, if they get really stumped, the solution is available to download, too.