Peter Egermann (Robert Atzorn), from a privileged background, has just killed prostitute Katarina Krafft (Rita Russek), "Ka" to most who know her, a fact that he has informed his longtime friend and therapist Mogens Jensen (Martin Benrath), a professor of psychiatry, to help him deal with and understand it. Two weeks earlier, Peter had mentioned to Mogens that he was having homicidal thoughts of killing his own wife, Katarina Egermann (Christine Buchegger), despite the two loving each other in their own way, including having a symbiotic sex life. Mogens' initial thoughts are that Ka was either meant to be a prelude to killing Katarina or surrogate instead of Katarina. Several episodes in Peter and Katarina's joint and individual lives leading up to the murder are presented which may provide some insight into Peter's homicidal mindset. Several post-murder episodes related to the event are also presented, most of them interviews by the Inspector leading the investigation, including one with Peter's self-absorbed and overbearing actress mother Cordelia Egermann (Lola Müthel), and another with Katarina's homosexual business partner Tim Mandelbaum (Walter Schmidinger). All of these episodes lead to Mogens providing his own professional assessment of Peter and the murder.
—Huggo