Karolina is an ambitious community police officer. She's trying to locate her father, a legendary Warsaw police officer, who has been missing for a year. His disappearance negatively impacts Karolina's relationship with her mother Irena and her sister Ewa. During a seemingly trifling intervention, Karolina finds a murder victim in a booze-den. Her search for the suspect captures the attention of Michal, a go-getting crime unit officer, while the disappearance of her father takes an unexpected turn.

The autopsy confirms the worst suspicions. Karolina and her sister try to inform their mother about the discovery of the body, but they cannot contact her. Is it possible that the woman knows much more than she claimed? At the same time, Karolina At her own request, she is assigned to investigate a murder in a den. He becomes acquainted with the suspect's girlfriend, Jagoda, who claims that her boyfriend was framed.

Irena is arrested. Her stay there is a shock, and her fellow prisoners seem hostile. Karolina, convinced of her mother's innocence, starts her own investigation. Meanwhile, Jagoda gives Karolina and Michał another clue in the case murders in the den. Karolina follows her father's recent affairs and makes a surprising discovery in her parents' house.

Irena manages to gain the respect of the prisoners in her cell. Karolina and Michał trace the connections between the people involved in the murder in the den and discover who withdrew the money from the victim's account. At the same time, Karolina tries to decipher the data from the notebook father and reveals to Michał that he is conducting a private investigation. Together they reach an abandoned premises and find traces of a dangerous practice.

The prisoners from Irena's cell plan to escape, but not everything goes according to plan and a tragedy occurs. Karolina cannot come to terms with what she learned about her father. At the same time, he realizes that he could not act alone. During the Holidays Michał and his colleagues are trying to solve the murder case in the den, but Karolina still has doubts about the guilt of the arrested person. Michał decides to check her suspicions one last time

Karolina is tormented by remorse about Michał, who is fighting for his life in the hospital. During a conversation with Ewa, it turns out that her sister knew more about her parents' relationship than she did. Karolina confronts the suspect in her father's murder. This she directs her suspicions at someone whom Karolina trusts implicitly. Meanwhile, a new prisoner arrives in Irena's custody. Both Karolina and her mother are in mortal danger