A look at the world of cryptic crosswords, offering up the secrets of these seemingly impenetrable puzzles. Crossword setter Don Manley, AKA Quixote, reveals the tricks that compilers use to bamboozle and entertain solvers using a crossword he created especially for the programme. We also find out why Britain became home to the cryptic crossword, how a crossword nearly put paid to the D-Day invasion and why London Underground is elevating the crossword to an art form. Author Colin Dexter explains why Inspector Morse loved his crossword, Martin Bell reveals how his father became the first crossword setter of the Times without ever having solved one and the crossword editor of the Daily Telegraph opens up her postbag. Also sharing their enthusiasm for cryptic crosswords are actors Prunella Scales and Simon Russell Beale, Val Gilbert of the Daily Telegraph and Jonathan Crowther, AKA Azed of the Times.