He was one of the most effective agents ever to work for Soviet Russia. For the first half of the twentieth century his fingerprints can be found on one world-changing event after another. But who was Otto Katz? To the FBI, he was 'an extremely dangerous man'. The British Secret Service wondered if he was the 'Director of all Communist policy in the West.' In Prague and Berlin he was a drinking companion with the likes of Franz Kafka and Bertolt Brecht. To Marlene Dietrich, he was one of her many lovers. But to others, Katz was a passionate anti-fascist who witnessed Hitler's rise to power and was among the first to alert the world to the Nazi threat. He was a staunch Communist, part of the Soviet infiltration of England during the period when the Cambridge spies were being recruited. In Hollywood, he was a playboy socialite, political mentor to director Fritz Lang and a star among stars. His example inspired the character of Victor Laszlo in Casablanca and Kurt Muller, the hero of the Academy Award Winning Watch on the Rhine. To Noel Coward, he was a potential double agent. In the Spanish Civil War, he did Stalin's dirty work. Years later, some even blamed him for the assassination of Trotsky. In a captivating detective story, Jonathan Miles goes in search of the real Otto Katz - a brilliant, daring charmer, a double-dealing man with an unquestionable taste for the finer things in life who, nonetheless, served one of history's darkest masters - Joseph Stalin. Using recently released FBI, MI5 and Czech files, Jonathan Miles has created an action-packed story of the life (or lives) of one of the world's most intriguing, influential and successful spies.