Pupils are being challenged to put their codebreaking skills to the test in a festive brainteaser set by the UK's intelligence agency GCHQ.
The puzzle features on a Christmas card sent by Sir Jeremy Fleming, director of the Cheltenham-based spy agency.
Secondary schools across the country are trying to crack the code, intended to test problem-solving skills.
"Puzzlers need to combine a mix of minds to solve the seemingly impossible," said Sir Jeremy.
The Christmas card features seven "fiendish" puzzles and is aimed at testing schoolchildren's knowledge of key subjects and their ability to work as a team.
"The puzzles are based on the seven disciplines of languages, engineering, codebreaking, analysis, maths, coding and cybersecurity – all key skills needed at GCHQ to help keep the country safe," a spokesman said.
But this year's challenge comes with an added twist, as once all the puzzles are solved, schoolchildren will then need to use the design on the front of the card to assemble the answers in order to form three locations.
Joining those place names together will reveal the final answer.
The intelligence agency said pupils would need to employ all their skills of lateral thinking, ingenuity and perseverance to be successful.
"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," said Sir Jeremy.
"This year's GCHQ Christmas Card Challenge gives an insight into the skills we need every day as part of our mission," he added.
Schools interested in taking part can find a resource pack on the GCHQ website.
Follow BBC West on Facebook, Twitter and Instagram. Send your story ideas to: bristol@bbc.co.uk
GCHQ book raises £5,585 for forces charity
UK spies change nationality rules for new recruits
Charles charity funded hard-up spies with Bond cash
GCHQ – GCHQ.GOV.UK
South West weather: Met Office issues yellow weather warning for ice
Five vehicles destroyed in fire off A44 near Moreton
Update issued after man arrested for murder in Cheltenham
Gloucestershire children's services blame overspend on complex cases
'Why it is right to take strike action'
Minor unit in Stroud closes amid nurses strike
Power cuts in six states as deadly storm hits US
Deadly attack leaves whole of Kherson without power
US brings back free at-home Covid tests
'My boss made me wash the men's towels at the office'
Is India seeing a surge in grisly copycat murders?
Hungary's risky bet on Russia's nuclear power
'If he is still alive, where is he?'
Despair and pride for Moroccans at World Cup exit
How a British special forces raid went fatally wrong
Covid wave batters China's overstretched hospitals
Nuclear fusion breakthrough – what is it and how does it work?
The silent struggles of ADHD workers
The French breakfast you don't know
The rise of the remote helicopter boss
The underwater sounds that can kill
© 2022 BBC. The BBC is not responsible for the content of external sites. Read about our approach to external linking.
