While on honeymoon in Vienna in June, 1998 - at the height of the tourist season - Gerald Daniel Blanchard, an accomplished thief, happened upon the greatest challenge of his life when he spotted the last remaining "Sisi Star" on display in Schonbrunn Palace. Named after its former owner, the Empress Elisabeth, the ten-pointed diamond and pearl star was originally one of 27 that the enigmatic Sisi wore in her extravagantly long hair. Despite the multi-layered security system protecting the priceless jewelry, Blanchard decided then and there to steal it. The star remained missing for nine years until two Canadian police investigators launched a joint task force to bring down a criminal organization that had robbed banks, stores and ordinary citizens on several continents. When their chief suspect offered to reveal the whereabouts of the Sisi Star, the investigators realized they were dealing with no ordinary thief. But no one involved in the case fully understood the history of the star, its ties to obsession, suicide and assassination.

Born into one of 19th century Europe's more powerful families, Archduchess Marie Valerie was the favorite daughter of her father, Austria's Emperor Franz Joseph, and her mother, Empress Elisabeth. A sensitive young woman, she was determined to marry for love and in 1890 wed her cousin, Franz Salvator of Tuscany, and bore him 10 children. The dashing Archduke was not faithful to his devoted wife. His affair with Stephanie Richter, a young, middle-class Jewish woman with a knack for flattering powerful men, lead to an illegitimate child, a royal title of her own and a career as a double-agent in the prelude to World War II. Princess Stephanie von Hohenlohe became vital to Adolf Hitler, betrayed the German Jews, the British government, and her home country of Austria-until Hitler betrayed her, leaving her without allies or protectors.