An international group of researchers has cracked the code in letters written by Mary Queen of Scots. The letters were discovered in France’s Bibliothèque Nationale de France in Paris. Mary Queen of Scots spent the last 20 years of her life imprisoned by her cousin, Queen Elizabeth I, before being executed in 1587. The World’s Marco Werman speaks with George Lasry, the leader of the codebreakers, about their discovery and what the letters contain.