A serial killer is on the loose in summer in Franconia, targeting all his victims at popular festivals: the Samba Festival in Coburg, the Bergkirchweih in Erlangen, the Africa Festival in Würzburg, and the Bardentreffen in Nuremberg. His gruesome calling card: a 'House of Nikolaus' etched into the victims' skin. Commissioner Charly Herrmann leads the SOKO Franken in his own stubborn and determined way. Hysterical media ('Nik the Ripper!'), highly nervous superiors, and a Bavarian profiler do not throw him off track – until the murderer hits Charly's sore spot.