"Sudoku X" is a brand new and irrestistable twist on the sensational worldwide puzzle craze. It offers something new that no other Sudoku puzzle has offered before, the instantly recognisable 'X' factor formed by the diagonals. The first "Sudoku X" book looks set to be a big seller for Headline, throughout the world, helped by the extensive coverage in the "Daily Mail" for the puzzles. This second book has an even greater range of puzzles, using different grids, and even letters. They range in difficulty from 6-by-6 puzzles children can complete through "Super Sudoku X" (as seen in the "Mail's Weekend magazine") and brand new 'snowflake' puzzles to hugely complicated 16-by-16 puzzles to test the real experts. With a festive theme, "Sudoku X-Mas" is the perfect stocking filler for every member of the family.