Are you a Sudoku addict and searching for a new high? Help is at hand with Hitori, which can be thought of as a kind of "inverse" Sudoku. The intrepid player is presented with a grid in which every square contains a number. The aim of the game is to shade in squares so that no number appears twice in any one row or column—while making sure shaded squares never touch. What's more, unshaded squares must form a single continuous area, being in contact with another unshaded square on at least one side. This compulsive collection features more than 100 all-new puzzles of increasing difficulty. The book also contains a full introduction, player's guide, hints, tips, and solutions if you get really stuck. So if you think you've got Sudoku figured out, try Hitori—the gripping game that's so good, you'll be desperate for your daily fix. Gareth Moore's previous book wasThe Book of Kakuro and How To Solve It.