Set your watch to 30 minutes, because that's how long you have to finish each of these 72 fiendish, timed crosswords. They're created by some of the members of CrosSynergy, a syndicate of a dozen top puzzlemakers. None of their puzzles see the light of day until it has gone through a brainstorming and peer review process; along the way, reviewers weed out obscure or unsuitable words, and if anyone feels that a clue is unclear it's eliminated. That's...