At the same time, Werthen is commissioned to locate a missing letter from the emperor to his mistress. Franz Josef is desperate for the letter not to fall into the wrong hands – but what incendiary information does it contain?
As Werthen and his colleague, renowned criminologist Dr Hanns Gross, pursue their investigations, it becomes increasingly clear that there is a connection between the two cases – and that the future of the empire may be at stake.