Jingle bells on the Kiel Fjord: while Commissioner Borowski and his colleague Sarah Brandt are celebrating Julklapp in the Presidium, a murderer is preparing a dark crime in neighboring Schleswig. At the Lucia Festival parade at a Danish school, a man suddenly caught fire. Kriminalrat Schladitz, who spent his childhood in this place, becomes an involuntary witness to the brutal attack. The dead man, Michael Eckart, was the headmaster here and is a member of the Danish minority. At first everything indicates that the murderer can be found in the immediate vicinity of the dead man.

Bibi Fellner tackles the case of a twelve-year-old boy accused of a brutal act of violence.

A nighttime emergency call from a moving car alerts the police in Carinthia: "Eisner, BKA Vienna, service number 318-12-58. Need support!" A short time later, Lieutenant Colonel Moritz Eisner is found seriously wounded by a shot to the head and motionless behind the wheel of his car in a quarry. When he wakes up in the intensive care unit, he has no idea what has happened. He suffers from "retrograde amnesia", which blocks out the traumatic experience itself. A fatal consequence of the gunshot wound.

A failed assassination attempt at a major international conference leads Eisner and Fellner into danger.

Lürsen and Stedefreund embark on a controversial murder investigation.