GCHQ in Cheltenham has released its 2019 Christmas card puzzle.
Colleagues at the organisation, responsible for intelligence and security across the country, have put their minds together to create this year's festive conundrum.
Read more: Try out more GCHQ puzzles
GCHQ Director Jeremy Fleming has sent the same Christmas card brain teaser to colleagues and partners across the world - and now you can have a go too.
Check out the puzzle here.
The conundrum combines a codebreaking message and a classic Soduku theme, with the following instructions issued by the organisation:
Work out the message that snakes its way through the snowflake
Colour in the snowflake so that each circle of six hexagons surrounding a grey hexagon uses each of the six colours once
Work out the significance of the coloured snowflakes – you might need a ruler!
A spokesperson for GCHQ said: