Challenge yourself at home with word and number puzzles Specially compiled to provide the most devilishly difficult challenge, Ultimate killer Su Doku 3 is the only volume for Su Doku enthusiasts who need a puzzle that really tests their mettle. Prepare yourself for the toughest Su Doku challenge there is. These diabolically difficult Ultimate Killer Su Dokus will really put your brainpower to the test as you warm up with the 100 Deadly...