If you love Sudoku and are ready to take it to the next level, this is the book for you Are you up to the challenge? You will be solving several Sudoku puzzles simultaneously. If you get stuck in one grid, switch to a different grid for a while. When you're working in the overlap boxes, you may get clues from both of the Sudoku grids This collection of puzzles is the latest from Professor Einstumper He has over 150 puzzles in this book that will provide you hours and hours of entertainment.