 Mysterious murder cases happen during the investigations, done by the malicious botanist Baron von Kratzmar and his carnivorous plant Adela.Von Kratzmar kidnapped his victims, bound them and whenever he played a gramophone with the melody "Schlafe, mein Prinzchen" (a lullaby by Bernhard Flies but previously associated with Wolfgang Amadeus Mozart) it is the time for Adela to awaken and eat her victims for dinner.Baron von Kratzmar considered himself a misjudged genius and wanted to take revenge on one of his former professors.