The levels of difficulty have slightly been increased You've been warned Contents: 100 Killer Sudoku 10 Killer Sudoku with diagonal cages 10 NON-CONSecutive Killer Sudoku X and 30 ZERO Killer Sudoku (blank cages) Difficulty levels are the usual EASY-COOL-THINKER-BRAIN-IQ, except that there are no EASY puzzles. Most puzzles are of THINKER and BRAIN difficulties, with lots of IQs, too. Zero Killer Sudoku puzzles are mostly IQs, of course. All puzzles in this book are NEW. This is certainly the darkest and the bloodiest Killer Sudoku book you'll find