The residents of Regensburg are shocked. The body of 19-year-old Biljana Savic (Cordula Böck) is recovered from a branch of the Danube. The scars on the girl's body allow only one conclusion: murder. What particularly affects Commissioner Lucas (Ulrike Kriener) is the fact that the traces of abuse in the past as well as the present suggest. From Biljana's friend Milica (Miranda Leonhardt) she learns that both girls came to Regensburg two years ago through an au pair agency from Serbia. Young Milica looks frightened and refuses to comment further. Biljana's host parents, the Schwarz couple (Anneke Kim Sarnau and Felix Eitner), also remain silent.
What drives Milica into isolation and what is the couple hiding? In order to break the wall of silence, the commissioner turns to Father Danko, a priest from Croatia who knows how to relate the horrors of war in the recent past. The Croatian Tomislav Vodenac (Peter Davor), with whom Milica was being treated by a dentist, represents a completely different victim/perpetrator theory of the war. His relationship with Milica's host mother Isabell (Maria Bachmann) makes him suspicious. The situation escalates when inspector Lucas receives life-threatening threats and the unknown assailants do not shy away from attacking their landlord Max (Tilo Prückner).
Inspector Lucas can only understand how the crime is related to the recent European past when it is almost too late, because suddenly Milica has disappeared ...