GCHQ are back at it again with another fiendishly difficult puzzle, and this time it’s festive.

Posting on social media, the spy agency said its latest quiz was aimed at children with an interest in STEM subjects – that’s science, technology, engineering and maths – and offered participants the chance to “discover their inner intelligence officer” by having a go at the seven puzzles, which increase in difficulty, in their Christmas card.

The GCHQ Christmas card is traditionally sent to other spy agencies and partners across the world. In this year’s quiz, people have to answer seven questions, each aimed at different age groups from 11 to 18, then link them to a glowing node on the Christmas tree. Once complete, the tree shows a hidden message read from top to bottom.

So let’s have a go.


Sign up to our free Indy100 weekly newsletter

Twitter/ @GCHQ

Twitter/ @GCHQ


The Telegraph have got hold of the answers, which are as follows:

1. The initial letters of all the words in the question spell CHRISTMAS. This word is most closely related to the image of a present, located on the lowest bauble on the tree.

2. The 1-Across and 1-Down answers both spell THIS, which should be placed on the second lowest bauble with an image of stag (the word ‘stag’ is one of the answers in the crossword, along with ‘hoot’ and ‘Iowa’).

3. The missing word is THE. The list is the four Hogwarts houses from Harry Potter, in alphabetical order, but with 0, 1, 2, and then 3 letters removed from the srat and end of the names: GRYFFINDOR, hUFFLEPUFf, raVENCLaw, slyTHErin. This word should be placed on the lightning bolt, second from the top.

4. The squares without mines in the four areas of the grid form the shape of the letters SAFE. This word should be placed on the padlock, furthest left on the tree.

5. The answer is KINGDOM. The Taxonomic rank mnemonic has the same initials as Domain, Kingdom, Phylum, Order, Family, Genus, Species and Variety. This word should be placed on the crown bauble.

6. The answer is UNITED. The letters in the complete circles form the names MANCHESTER, NEWCASTLE and LEEDS, all premier league football clubs which end with ‘United’. This word should go on the football bauble.

7. The answer is KEEPING. This is a substitution code in which each letter of the alphabet has been replaced by a different one. The start point is the ‘cw’ after the number 7 which one can assume means ‘th’. From there the word ‘the’ can easily be deciphered, which in turn allows more words to be revealed. The result of the clue is ‘BOOMERS’ which, when put through the same substitution, becomes KEEPING. This word should be placed on the top bauble, marked by a pram in line with the reference to baby boomers.



GCHQ are certified puzzle fiends. You can have a crack at some of their other puzzles here and here.

Please log in or register to upvote this article
The Conversation (0)