Two Girls, One on Each Knee: A History of Cryptic Crosswords is an audaciously constructed book on the pleasures and puzzles of cryptic crosswords and their linguistic wordplay, from Alan Connor, the Guardian's writer on crosswords. On 21 December 2013, the crossword puzzle will be 100 years old. In the century since its birth, it 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. Alan Connor writes twice-weekly about crosswords for the Guardian. He has contributed pieces about language for the BBC and the Guardian and works in radio and television, writing with Charlie Brooker and Sue Perkins. His most recent writing was A Young Doctor's Notebook, a TV adaptation of Mikhail Bulgakov stories starring Daniel Radcliffe and Jon Hamm.