John Le Carré is one of the most celebrated writers of his generation. His novel, The Spy Who Came in from the Cold, published in 1963, was the first of several books that established him as one of the great novelists of the twentieth century. His literary talent combined with his experiences working for the British Intelligence Services, MI5 and MI6, have contributed to his reputation as a definitive writer of spy fiction. His novels Tinker, Tailor, Solider, Spy and Smiley's People were produced by the BBC for television and both starred Sir Alec Guinness. Several of his novels have been adapted for the cinema, including The Tailor of Panama (2001), the Academy Award winning The Constant Gardner (2005) starring Ralph Finnes and Rachel Weisz, and Tinker, Tailor, Soldier, Spy (2011) starring Gary Oldman, Colin Firth and John Hurt. In this extract from the inaugural World Book Night event in Trafalgar Square he reads from The Spy Who Came in from the Cold.