Ninja Assassin Sudoku Blue Belt Author:Frank Longo Many play sudoku, but only a select few reach the pinnacle of puzzle mastery. Now, with Ninja Assassin Sudoku, you can work your way up from white-belt status all the way to the elite black belt in books that grow steadily more challenging . . . and fun. White Belt may start gently, but don't be fooled-you will be tested in these pages. Just re... more »member: what doesn't kill you only makes you stronger!« less