The events revolve around Nadine, who works as a data analyst. She goes for a job interview, but she did not know that this interview would turn her life upside down, and the events continue.
Follows Detective Holly O'Rourke and her homicide team as a seemingly open-and-shut murder investigation threatens to destroy her career, her family, and her faith in justice. As she scrambles to redeem her personal and professional reputation, Holly and her team uncover a criminal conspiracy that will change their lives forever.
Songwon Police Violent Crimes Unit 2 has the lowest arrest rate in the country. After their chief is demoted, the team is exiled to a closed daycare center. Enter Yubin, their new leader. Despite the team's initial distrust, Yubin and the team start to bond as they solve cases together.