The junior member of Seoul's Special Intelligence Team (SIT), Kiana Park (aka Kim) finally got to lead her first team for a modus operandi under the guidance of her step-brother, Park Seojoon. But teaming up with Gangnam HQ and becoming direct partner of Mr arrogant hot and cold Im Siwan already had her fuming everyday. Just as she got over the relationship obstacle, she got stuck into deeper mud that her into because of her past that threatened to jeopardize her career and people she loved.