Two Girls, One on Each Knee. The Puzzling, Playful World of the Crossword; Penguin, 2014

In the century since its birth, the crossword has evolved into the world's most popular intellectual pastime: a unique form of wordplay, the codes and conventions of which are open to anyone masochistic enough to get addicted. In Two Girls, One on Each Knee, Alan Connor celebrates the wit, ingenuity and frustration of setting and solving puzzles. From the beaches of D-Day to the imaginary worlds of three-dimensional crosswords, to the British school teachers and journalists who turned the form into the fiendish sport it is today, encompassing the most challenging clues, particular tricks, the world's greatest setters and famous solvers, PG Wodehouse and the torturers of the Spanish Inquisition, this is an ingenious book for lovers of this very particular form of wordplay.