The recently divorced father of a nine-year-old, furious his daughter can't spend her birthday with him, bursts into her classroom with a birthday cake and a rifle. A hostage crisis ensues, and the mayor of the town in which the events take place will try to use the situation to gain advantage ahead of the elections, stopping at nothing. The son of a young policeman is in the same class, and before the events unfold, he'll have to answer a question as well.

ZG80 is a prequel of Metastaze. The movie brings back its characters to prewar Yugoslavia where they, as part of Bad Blue Boys, go on a football match in Belgrade to see Dinamo play against Crvena Zvezda. They encounter guest fans, their arch rivals Delije, in a series of events that lead to football fans war on the streets of Belgrade.