In "The Black House" Klara Blum and Kai Perlmann investigate an artists' colony on Lake Constance. What appears to be a creative idyll turns into an uproar when the painter Martin Neumann is electrocuted in extremely cold blood. Klara and Perlmann are still in the process of finding out who was friend or foe in the rough painter's environment when a second murder occurs. Klara Blum is amazed to find that the perpetrator apparently used the bestsellers by crime author Ruben Rath as a template for his murders. Just wondering why? And can Klara, supported by Kai Perlmann, prevent him from continuing his cruel game?