Mi-Young, who used to be considered the Major Crimes Unit's top cop, is stationed behind a desk after having a baby. She leads uneventful yet peaceful days at handling civil complaints and looking after her son and unemployed husband at home. One day, an overly enthusiastic detective Ji-Hye, is consigned to Mi-Young's team, and they bicker over every little thing from the moment they meet. In fact, they are sisters-in-law, and neither are happy about sitting next to each other all day in the same office. But differences are pushed aside when a woman who came to file a report gets run over in front of Mi-Young and Ji-Hye. They discover that the woman is the victim of 'spy cam porn' and was threatened it would go up on a community site in three days. The two cops take the case, but due to workload, no one can handle it in time. Ji-Hye's burning passion for justice rekindles Mi-Young's sense of duty, and the two decide to take matters into their own hands.