This year’s GCHQ Christmas Challenge is now live. Devised by Government Communications Headquarters, the British intelligence agency, this year’s quiz presents seven puzzles for children aged 11-18. They’re designed to test a range of problem-solving skills, including creativity and intuitive reasoning.

Agency director Anne Keast-Butler said: “Puzzles are at the heart of GCHQ’s work to keep the country safe from hostile states, terrorists and criminals; challenging our teams to think creatively and analytically every day.”