LKA investigator Annalena Gottknecht believes her colleague Maik Briegand wants to protect a suspect, his old friend, the homeless Oliver Bartko. His DNA was found among others on the body. She begins to distrust Maik. Something from their past seems to connect the two men. Does it have to do with Oliver not being able to be in enclosed spaces? The 17-year-old murder victim, Ramona, had saved up a considerable amount from drug deals and had applied to the youth welfare office for guardianship of her little half-brother when she would soon come of age. The investigators find out: She wanted to get away with him - together with the suspect Yuri Schavadenov. There are conflicts between Briegand's former in-laws, who worked as miners, and his daughter Jackie, who is actively opposed to brown coal mining and has joined a group of climate activists preparing a major action on the edge of the open pit. Maik learns from his mother-in-law that Oliver is still working in her garden as before. Florian Langendorff, the new friend of his ex-wife Daniela, is anything but enthusiastic about this support. While Maik tries to rebuild the fragile relationship of trust with Oliver in the garden, Langendorff calls the police.

Homeless suspect Oliver Bartko is in police custody, panicking in his cell and rampaging. Investigator Maik Briegand can hardly bear to see his friend suffer. Against all regulations, he takes him outside so he can calm down. When Maik's colleague Annalena wants to take Oliver back to the cell, the situation escalates, with dire consequences.

The LKA investigators Maik Briegand and Annalena Gottknecht put Florian Langendorff, the friend of Maik's ex-wife, under pressure during the interrogation. Finally he admits that the murder victim Ramona sold him coke. But he denies killing her.