The body of Roy Wei slot, who worked at the tapping plant, is discovered in the blast furnace slag of a steelworks near Weimar. Inspectors Kira Dorn and Lessing quickly realize that he was murdered. Roy lived with his sister Siegrid, with whom, according to Siegrid, he had a close relationship. But the commissars find out that there was a war between the siblings, against which the battle of Jena and Auerstedt was a lesser dispute. Siegrid apparently hated her brother. She blamed Roy for her destroyed happiness in life with her ex-fiancé Karsten aka "Flamingo", who lost a leg through Roy's fault. This tragic event was the beginning of an unprecedented downward spiral for Karsten. Now he lives as an alcoholic wreck in an abandoned gas station.
And Karsten worked an extra shift at the blast furnace on the night of the murder, he is a possible culprit, as is his buddy Frank. He is connected to the prostitute Irina Kratochvílová, alias Vanessa Fink, who works in a mobile home on the outskirts of town. The detectives find out that Irina was hired by Frank and Karsten, who wants revenge on Roy, to extort money from Roy. The investigation is made more difficult by the fact that the inspectors have different ideas about the domestic future of their small family. Lessing has the unsettling thought that Kira might want to leave Weimar. In addition, the inspectors have to deal with their new colleague Ganser from forensic technology, who, as their boss Kurt Stich aptly puts it, is "a real ass cracker".