Forget cryptic crosswords, and put your sudoku down: the UK's spy agency GCHQ has sent out a Christmas card with a puzzle that even James Bond might struggle with.
As part of his annual Christmas card message the agency's director Robert Hannigan has sent out a brainteaser this festive season so anyone can test their brain power.
The puzzle is the first in a series of clues, but to what end, no one has yet deciphered.
Those who solve the final clue have been invited to submit their answer for the chance to win. Though exactly what prize is up for grabs has not been revealed. To be the next real-life Bond? Who can say.
"By solving this first puzzle players will create an image that leads to a series of increasingly complex challenges," said GCHQ.
Here's the first puzzle to solve:
Stumped? Here's their tidbit of guidance:
In this type of grid-shading puzzle, each square is either black or white. Some of the black squares have already been filled in for you.
Each row or column is labelled with a string of numbers. The numbers indicate the length of all consecutive runs of black squares, and are displayed in the order that the runs appear in that line. For example, a label "2 1 6" indicates sets of two, one and six black squares, each of which will have at least one white square separating them.
Click on the picture to download to get cracking on the puzzle. GCHQ has given wannabe agents until 31 January to submit their answer and is also asking anyone who has a go at it to make a donation to the NSPCC.