This adaptation of author Sing's book for older readers traces the history of the secret language of codes, from Mary Queen of Scots's conspiratorial codes to the famed breaking of the German's Enigma machine by British cryptanalysts in World War II.

Simon Lehna Singh,(born 1964) is a British Indian author of Punjabi background, who has specialised in writing about mathematical and scientific topics in an accessible manner. He is the youngest of three brothers, his eldest brother being Tom Singh, the founder of the UK New Look chain of stores.

His written works include Fermat's Last Theorem (in the United States titled Fermat's Enigma: The Epic Quest to Solve the World's Greatest Mathematical Problem), The Code Book (about cryptography and its history), Big Bang (about the Big Bang theory and the origins of the universe) and Trick or Treatment? Alternative Medicine on Trial (about complementary and alternative medicine).

He has also produced documentaries and works for television to accompany his books, is a trustee of NESTA, the National Museum of Science and Industry and co-founded the Undergraduate Ambassadors Scheme.

In 2008, Singh was sued for libel by the British Chiropractic Association for criticising their activities in a column in The Guardian.[1] A backlash to the lawsuit is occurring, with Nature Medicine noting that the case has gathered wide support for Singh from thousands of scientists, journalists and parliamentarians, as well as prompting calls for the reform of libel law.