The Official Utterly Addictive Number-Placing PuzzleWill solving these all-new Fiendish Su Doku puzzles scare you speechless while giving you the ultimate challenge? Providing hours of entertainment, Su Doku engages your mind, improves your concentration, and helps you stay mentally fit. With 150 brand-new puzzles to complete, you'll become a Su Doku master in no time! | New York Post Scary Su Doku by None None, Paperback | Indigo Chapters