HA Yoon-ju who possesses a crystal clear memory, keen observation, and the utmost concentration skills, becomes the newest member to a unit within the Korean Police Force's Special Crimes Unit (SCU) that specializes in surveillance activities on high profile criminals. She is assigned under Hwang Sang-jun, the veteran leader of the unit, who is rough, reckless, but warmhearted and known for his animal-like senses and intuition. The two gradually develop a close partnership when they attempt to track down James, who is the cold-hearted leader of an armed criminal organization. Using his unmatched intelligence and strategy, James manages to evade their radar every time. Now, Hwang Sang-jun and Ha Yoon-ju must do everything they can in order to find him and stop him.