Will Shortz Presents Black Diamond Sudoku: 200 Extreme Puzzles

Watch out! These puzzles are for the most extreme solvers! But if you dare, grab a pen and take on these two hundred all-new extra challenging puzzles in Will Shortz Presents Black Diamond Sudoku.

Features:
- 200 hard puzzles
- Big grids for easy solving
- Introduction by legendary puzzlemaster Will Shortz