"Count Alessandro Di Cagliostro (aka Giuseppe Balsamo) was an eighteenth-century Janus agent, alchemist, and expert forger best known for the Affair of the Diamond Necklace. It is believed that Cagliostro helped try to steal a magnificent diamond necklace that a Paris jeweler wanted to sell to Marie Antoinette, the queen of France. Cagliostro may have been involved in coaching a young woman to impersonate Marie Antoinette for this theft. What is known is that Cagliostro had a serious interest in the French crown jewels...and no one will say why."