1985 — Season 1

Marc and his friend Franky begin a career in the Gendarmerie. The corps is in a deep crisis after the discovery of the drug trafficking of one of the officers by Major Vernaillen. Marc is able to start as the major's secretary, placing himself at the heart of the internal struggle of the gendarmerie. Meanwhile, Franky is noticed by Madani Bouhouche, a gendarme who considers himself above the law. Franky's sister Vicky, who is a student at the University of Brussels distances herself from her brother and Marc because, as gendarmes, they are unpopular on the leftist university campus.

After the attack on Vernaillen, Marc is protected by his new superior, adjutant Goffinard. Franky defends his superior officer, adjutant Debels, who went way out of line in a racist incident. In return, Debels introduces Franky to Group G, a shadowy organization of far-right gendarmes. Madani Bouhouche seeks revenge after his dismissal from the Gendarmerie.

Marc discovers, together with Goffinard, that there is a link between several, at first sight not linked violent crimes. But Goffinard forbids Marc from sharing that info with other services. He doesn't want any prying eyes. Franky gradually becomes entangled in the far-right network. Vicky misses her brother but fails to find Franky. Marc, on the other hand, secretly goes to the parties where Vicky is a DJ. Major Vernaillen becomes increasingly isolated.

At a demonstration, Marc as a gendarme and Vicky as an activist face each other. When Marc is attacked by a group of students , Vicky saves him. It brings them closer together. As a reward for his discretion, Franky is allowed an internship with the Special Forces Brigade Diane. Marc and Goffinard discover that several of the recent murders can be linked. Vernaillen is secretly conducting a parallel investigation.

Marc and Vicky try to keep their relationship a secret from the outside world, but discussions about drugs and their opposing political views create tension. Franky gets to work as a security guard at a minister's private party. During a break-in at a supermarket in Nivelles, three people are cold-bloodedly executed, including a gendarme. The robbers lure a gendarme patrol and a police car into a deadly ambush; the Brabant Killers are born.

Vicky graduated as a lawyer and now lives with Marc. The latter conducts a secret investigation into the Gang together with Goffinard. Vernailing is promoted away. The Group G thinks that Marc is getting too curious about their activities. They send Franky after him. It becomes a painful confrontation between the two friends.

After several deadly raids, the Brabant Killers seem to have suddenly stopped their attacks. The investigation has stalled, and Marc has been transferred to a Gendarmerie department where he has to do administrative work, much to his frustration. Franky increasingly flees into hard drugs. Bouhouche is worried because Juan Mendez suspects him of stealing his weapons collection. Vernaillen continues to work on his private investigation and shares his findings with Marc. Vicky refuses to breach her duty of professional confidentiality as a lawyer to help Marc.

Bouhouche is arrested for the murder of his friend Mendez. Together with Goffinard, Marc eavesdrops on prison conversations between Bouhouche and his wife. This is how they find out where the Brabant Killers weapons are located. During the observation of that place, a confrontation occurs.