Host Simon Singh examines the secretive history behind the development and evolution of ciphers and code breaking. Thestories in the series range from the cipher that sealed the fate of Mary, Queen of Scots, to the coded Zimmermann Telegram that changed the course of the First World War.

Codebreakers: The Science of Secrecy brings to life the hidden history of codes and code breaking. Since the birth of writing, there has also been the need for secrecy. The story of codes is the story of the intellects who used mathematics, linguistics, machines, gut instinct, logic and detective work to encrypt and break these secrect messages and the effect their work has had on history.