Since its debut in The New York World on December 21, 1913, the crossword puzzle has enjoyed a rich and surprisingly lively existence. Alan Connor, a comic writer known for his exploration of all things crossword in The Guardian, covers every twist and turn: from the 1920s, when crosswords were considered a menace to productive society; to World War II, when they were used to recruit code breakers; to their starring role in a 2008 episode of The Simpsons.