Things are looking grim for Mick and Andreas: a colleague from the criminal investigation department is brutally murdered—and Mick and the entire department are suspected of being involved. The Internal Affairs Division, which assigns two tough officers, Caroline Hillebrecht and Falk Schröter, to the case, has evidence that Jonas was corrupt. And because he was about to spill the beans, the officers assume that someone wanted to silence him—someone from the department!

A dead butcher named Schill lies in the forest. Meisner faces a problem: the dead man has been completely drained of blood, and the wound on his neck does not match any weapon. Initial suspects include both the estranged widow and Schill's partner, a militant animal rights activist. When, on the morning after the body is found, several Essen residents end up in the city's hospitals with sausage poisoning, the investigation immediately takes a different turn.