Bettina Schnell from Ludwigshafen is about to take her final exams at the police academy when she is murdered. The young woman was known to her trainers as a particularly capable and ambitious candidate, as did the head of the school, Robert Brandstetter, who deeply regrets Bettina's death, especially since she was a friend of his son Torben. For Lena, meeting Brandstetter is a reunion, in her own training he was one of her mentors. However, the committed lecturer does not seem to have noticed that Bettina undertook independent investigations in her local neighborhood in her free time and in doing so made herself anything but popular. Lena and Kopper find evidence that points to a flourishing anabolic steroid trade in the vicinity of a fitness studio.
While they are still wondering whether the murder has anything to do with Bettina's investigations, the police students Torben and Heiner decide to take matters into their own hands... Bettina Schnell's body is found in a field near the Bayreuth settlement in Ludwigshafen found. Bettina grew up in this area, but currently lived mainly in the Hahn police academy because of her education. There Lena begins her investigations, while Kopper researches Bettina's last operation against the petty criminal Hasan Kiser. The police academy is familiar territory for Lena: she herself was trained in Hahn. Your former lecturer Robert Brandstetter is now head of the school, his son Torben was engaged to Bettina Schnell.
Brandstetter shows his great appreciation for Lena, but that is of little use to his son, who has withdrawn completely into his grief. The picture that Lena and Kopper get from their investigations of Bettina is ambiguous. Bettina Schnell was ambitious, determined to make something of herself and her life - not a matter of course in the milieu from which she came. She also encouraged her little sister Svenja and tried to give her a hold. In the police academy, the determined Bettina didn't have many friends besides her fiancé Torben, his buddy Heiner Struck and her roommate Sabine Erler.
Lena and Kopper realize that Bettina could also be overzealous and was rather ruthless towards people from her neighborhood when they reconstruct what the young policewoman was last busy with. She used her knowledge of the settlement to investigate old acquaintances on her own. So she observed Malte Boller's gym and hadn't accidentally caught Boller's buddy Hasan Kiser with a gun during a traffic stop. From Bettina's notes and photos, the inspectors conclude that the young woman believed she was on the trail of a booming anabolic steroids trade in the settlement. However, she hadn't been able to provide the ultimate proof, so the narcotics squad didn't take her tips into account. Questioned by Lena and Kopper, Malte Boller rejects all suspicions as unfounded.
But he and his boys get nervous and make mistakes, so Lena and Kopper stick to Boller's secret deals. While the suspicions in the direction of Malte Boller intensify, Lena is irritated. She cannot imagine why Robert Brandstetter didn't tell her anything about Bettina's investigations and a complaint by the drug squad against the police student. In any case, she increasingly has the impression that Brandstetter, despite his well-meaning façade, is more of a hindrance than a support to investigations at the police academy. At the same time, they are increasingly coming into focus. Peter Becker's trace analysis showed that Bettina was only brought to the settlement after her death - she was killed in a parking lot very close to the police academy.
So far, Lena has been of the opinion that Torben Brandstetter and Heiner Struck's nerves are so thin because they mourn the loss of a classmate. But what if the two are involved in the anabolic steroid trade and it was they who warned Bettina's opponents in good time about their observations? But when Lena and Kopper want to interrogate the police students again, the whole class is ordered to work..