The body of twelve-year-old Miriam Meinfeld is found in the Tenever district of Bremen. The police assume suicide. It turns out that the girl has had a history of sexual abuse and various old bone injuries point to abuse. The inspectors Inga Lürsen (Sabine Postel) and Stedefreund (Oliver Mommsen) first look for possible suspects in the family circle. They fear for the well-being of the two siblings Svenja (Luisa Sappelt) and Björn Meinfeld (Philip Stölken), since the parents (Michael Lott, Martina Schiesser) do not make a particularly trustworthy impression. However, the parents blame the residents of a home for the mentally handicapped, which has long been a thorn in the side of the residents of the district.
And indeed, the commissioners find traces of the deceased and her sister Svenja there. Harald, one of the disabled people (Hans Uwe Bauer), is arrested when it turns out that he is by no means as harmless as he appears at first glance, that he was an officer in a special unit of the Bundeswehr (KSK) until he suffered a severe head injury, so quite capable of physical violence. The suspicion against him increases mainly because he remains silent. The inspectors only realize much too late that they were deliberately misled, that Harald helped the two girls and gave them shelter. But by then it's already too late. A tattoo on the dead girl's hand puts officers on a whole new lead. It is the sign of a satanic sect.
Stedefreund comes across the librarian Karin Melzer (Monica Bleibtreu), who is familiar with the scene and gives him information. But what the woman says sounds so exaggerated and spooky that Inga Lürsen is initially unwilling to believe her. The commissioners only slowly find out that there are connections after all: the spooky rituals of the sect and the drugs that the children are given could, among other things, have the purpose of making all the statements made by the victims sound so improbable that nobody believes them. And so the inspectors can hardly find anyone who has really listened to the children, and they can't get close to the children.
This is ensured by the parents, from whom the viewer will later learn that they, originally victims of the sect themselves, are now part of the apparatus and make their children available for its rituals. The sect responds promptly to the threat. The informant dies in an accident. The Meinfelds are shot (even though it's meant to look like suicide) and the two children are kidnapped. With that, all witnesses are eliminated and the commissioners begin to understand that the sect's helpers are obviously sitting in high positions and have been monitoring and manipulating their every step for a long time.