The legal drama centers around Jang Hye Sung, a brazen, sharp-tongued female attorney who says everything that comes to her mind with no filter. When she gets to the point in her career where it's hard to muster up any enthusiasm for her work, she teams up with the serious Cha Kwan Woo, a passionate public defender, and Park Soo Ha, a 19-year-old high-school student with a special ability to hear people's inner thoughts. Seldom she knew that she has a past conncetion with Park Soo Ha. Together, they also must face a killer with a personal vendetta that entwines all of their lives. Can they bring the dangerous man to justice?

Two teenagers joining the same class in a high school die on the same day. The one to be top of the class is killed by a big knife on the street, the other - the second best of the class indeed - seems to be jumped from the top of the school building. Everybody believes that he first killed his classmate and than himself. But when the police finds small pill boxes into the stomachs of both kids confessing their murder two South Korean cops are torn into a new case of murder series. While they try to hunt down the serial killer, more pupils are getting killed...