Marina Kapov, a police station cleaner with sharp analytical skills, uncovers clues pointing to a third person in the death of Ana Tokić, challenging the initial assumptions of the investigation.

Marina joins the police team as a consultant, clashing with detective Ramljak while investigating Marko Katić’s suspicious death and confronting secrets tied to her missing ex-partner from fifteen years ago.

Marina and Detective Ramljak take over the investigation into the disappearance of young girls Mija and Tea following the murder of their father. While the clues lead toward family conflicts, custody battles, and business secrets, the police attempt to uncover what truly happened and find the girls before it is too late. The investigation reveals an increasingly complex web of lies, threats, and hidden motives.

The death of exotic animal veterinarian Fani Alavanja initially appears to be natural, but the clues found raise suspicions that there is something more behind her passing. The police investigation reveals complex relationships, hidden secrets, and details from Fani's life that shift the perspective on the case. In addition, Marina learns about an event that occurred in December 2010, which could be linked to Borna Horvat.

The attempted murder of Emil Kajić triggers an investigation that uncovers a complex web of false identities, family secrets, and hidden motives. Marina and Detective Ramljak discover that the story of his alleged daughter is not what it seems, and the clues lead them to a case involving a heart transplant. Meanwhile, Marina simultaneously confronts new details from her past and the questions raised by the story of Borna Horvat.

The murder of Jurica Vinković opens an investigation that leads from football disputes and fan violence to hidden relationships and personal motives. During the investigation, Marina and Detective Ramljak discover clues from the locker room, footage of Dora Marinov, and statements from people close to the victim, all of which reveals that a much more complex story hides behind the crime than it initially seemed.

The murder of Martin Mamić opens an investigation at a rowing club, where Marina and Detective Ramljak uncover a story of old disputes, threats, and past traumas. While the clues lead to Goran and Romana Spajić, further investigation reveals that their memories and testimonies might be part of a much larger manipulation.

Young figure skater Lidija Viculin is found run over by her own car. Her death opens an investigation that links her case to the previous murder of Nikola Zaninović. The clues lead Marina and Detective Ramljak to Lidija and Nikola's shared past, their old relationships, and events that reveal there is much more to this double tragedy than a simple accident.