A man (Ulrich) meets his sister (Agathe) after the death of their father. Having scarcely seen each other since childhood, brother and sister are strangers and yet there is a special sense of familiarity between them. Soon this develops into an intense bond which is both mystical and incestuous. They talk so as not to look each other in the eye. In a roundabout way, brother and sister do try to say the unsayable. In their moonlight conversations they explore the possibilities of a different, more authentic life.

But their shaky balancing act is rudely interrupted by the characters from Vienna’s beau monde who we met in the first part of the Musil cycle: the idealistic Diotima who has thrown herself into the study of sexology out of amorous frustration; the hysterical Clarisse who is infatuated by the rapist and murderer Moosbrugger; the conservative Count Leinsdorf who loses his grip on the preparations for the festivities in honour of the Emperor, and the naïve but cunning General Stumm von Bordwehr. During the official inauguration of a new wing in the psychiatric clinic, the border between insanity and normality becomes extremely thin... In the end Ulrich’s and Agathe’s utopian world proves unsustainable.