A Festive Sudoku: A Critical Line Puzzle

Hello again, puzzlers! To bring in the holiday season, I wrote you a Christmas tune! I have included some sheet music, so dust off your glockenspiels and play along if you’d like.

Your puzzle

In his down time, Santa reportedly loves solving Sudoku. Through centuries of practice, he has honed his puzzling prowess and can now complete the world’s hardest Sudoku.

To keep him busy until Christmas Eve, his elves have devised a devilish grid. They have assured him there is only a single correct solution.

Santa's elves have been busy... crafting this fiendish festive Sudoku

Think you’ve got the solution?

Submit your completed sudoku to [email protected] by Wednesday, 24 December. Include whether you want your name or an alias published alongside the solution if you’re in the first 10 solvers.

Since no one got the answer last time, a randomly selected correct answer from the first 10 solvers (named or not) of this puzzle will win a $100 voucher!

Revealing the solution

The solution will be revealed on Thursday 15 January 2026.