You probably already know that Sudoku puzzles involve all four lobes of the brain and provide one heckuva mental workout. And we should probably tell you that The Little Luxe Book of Sudoku from puzzlemaster Will Shortz has 345 Sudoku puzzles arranged by difficulty. So there, we said it. What we really want to talk about is the stunning package that’s wrapped around this mindbender. Hey, if you’re gonna flex your brain and do Sudoku on the train, you might as well send out a smart and sexy vibe while you’re at it. The Little Luxe Book of Sudoku makes a great gift for puzzle lovers—especially around Valentine’s Day.