Book excerpt: Think ordinary conundrums are just too humdrum? Do you finish crossword puzzles in ink and in no time flat? Then get ready for a serious test of your skills, with the ultimate in mental challenges. We've got crosswords of course; more than 50 tough, "regular" ones. But you'll also enjoy dozens and dozens more of different varieties, including devilish "Crushwords" where you have to put more than one letter in each square, and mind-blowing math and logic teasers known as pixel puzzles, where if your answers are correct you'll create a picture of success! And if that isn't enough, you'll also find word puzzles that demand "lateral thinking," and may well be the truest test of your abilities.