Secrets of the Dead – S23 E03 : Cracking the Queen's Code

In early 2003, three amateur codebreakers announced they had successfully decoded the secret correspondence of one of the most tragic characters in European history: Mary, Queen of Scots. 57 encrypted letters detail the exiled queen's efforts to free herself from imprisonment and gain advantage over her rival, Queen Elizabeth. Now, after four centuries, Mary's urgent pleas can be revealed.