Although referring to Townsend's The World's Most Challenging Puzzles, this quote is applicable to his entire puzzle canon. If you enjoy pitting yourself against the most challenging puzzles in existence and are a glutton for punishment, then one or all of these books are for you. Take your pick among "The World's Trickiest", "Super Brainy", "Most Perplexing", "Most Incredible", "Greatest", "Most Amazing", "Toughest", "Most Baffling", "Most Challenging",...