The young inspector Carolin has left her hometown after a failed relationship and started completely new. When Christmas is just around the corner, she tries to escape the festival of love with the help of her work. By chance, a strange helmet catches her eye, and as if on cue, it takes up all of her attention. A piece of evidence that seems to be associated with the mystical. But already at the first sighting of the old case, catastrophic investigative errors appear. Evidence is missing, witnesses disappear, and entire passages have been radically redacted. Even in the local forensics lab, the data on the case has been erased. So during Christmas, Carolin is drawn deep into the Michalski case, which already cost her predecessor her job a few years ago.