"Tetsuya Nishio is the undisputed grand ‘puzzle master’ of Sudoku: a bespectacled fiend from the darkest suburbs of Tokyo who spends his every waking hour devising abominable new ways to torture our brain cells. His only weapon is logic, but, in his own words, ‘it is a knife that kills.’ His commitment to deviousness is absolute." —The Times (U.K.)"Tetsuya Nishio has one of the world’s most creative puzzle-making minds. I’m a big fan." –Will Shortz, Crossword Editor, New York Times; Puzzlemaster, NPR.