Now that the link between the Rochat case and the murders of the girls is evident, the detectives decide to start again with investigations from the past. Thus they discover the identity of two witnesses of the old serial killer suicide. But what happened to the third? And where is his daughter now?

While detective Blum fights against the ghosts of his past, the search for the Meiers becomes increasingly frenetic. In fact, the team no longer has doubts: father and daughter are at the center of the serial killer's murderous fury. When a witness finally decides to reveal the murderer's identity, the end seems truly near.