Vienna, 1901. With the police seemingly indifferent to the murder of a 19-year-old prostitute known as Mitzi, brothel-keeper Frau Mutzenbacher turns to lawyer Karl Werthen to find out what happened and bring her killer to justice. Yet the more he discovers about the mysterious Mitzi, with her secret past and impressive roster of clients, the more questions Werthen's investigation throws up. At the same time, Werthen undertakes a second commission: to find out who viciously assaulted playwright Arthur Schnitzler. Schnitzler believes his latest controversial play might have been the motive for the attack - but is there more to it than that? As he navigates the highs and lows of Viennese society in dogged pursuit of the truth, Werthen finds himself drawn into a conspiracy of espionage and affairs of state.