Lawyer and private inquiries agent Karl Werthen is puzzling over the high-profile suicide of a city councilman-former client, next in line to Vienna's powerful Mayor Karl Lueger, and the last man Werthen would think capable of suicide. Werthen, however, has little time to ponder, summoned by wealthy industrialist Karl Wittgenstein (father of the future philosopher Ludwig) to find his oldest son, Hans, who has gone missing. Werthen soon discovers the whereabouts of the musically-minded Hans, and the case appears to be solved. But appearances are deceiving, and a simple missing person's case soon leads back to the councilman's suicide. Werthen, once again ably assisted by his wife, Berthe, and real-life father of criminology, Dr. Hanns Gross, journeys into a sinister web of deceit and violence that threatens not only his life, but also the very heart of the city and the empire.