Ma Yi-deum (Jung Ryeo-won) is a materialistic and ace female prosecutor. She walks a fine line between legal and illegal investigation of cases. She does not hesitate to use personal attacks, cook up evidence, and incite perjury in order to win her cases. At the same time, she is also a very ill-tempered and self-centered person. But she has a secret, a painful past that no one is aware of. One day, she is assigned to a special task force for sex crimes.

Yeo Jin-wook (Yoon Hyun-min) is a newbie prosecutor who just graduated from law school with top honors. He used to be a pediatric psychiatrist. He does not care about office politics, promotion and success. Due to his past career as a psychiatrist, he is able to identify truth by finding the subtle and hidden clues in people’s testimony. This is very beneficial and useful for solving sex crimes especially, which always lack physical evidence.

The two of them cannot stand each other initially, and hate each other’s guts. Yet, they still have to work as a team together to solve those crime cases. However, when Jin-wook found out about Yi-deum painful past and humble beginnings, he decides to protects and helps her.

Jo Gap-soo (Jun Kwang-ryul) is an ex-chief police officer. He was not able to become a prosecutor as his father was a left-wing activist under the right-wing government. Whenever he gets a chance to be promoted, he does not care about others that gets in his way. He will accuse them as communists to show his loyalty to the government. He does not hold any regrets to all the bad things he has done to others. After retiring as a police chief officer, he is elected as a member of the National Assembly. At the same time, he is a member of the advisory board of a law firm and is running for the mayor of Yeong-pa city.

Min Ji-sook (Kim Yeo-jin) is the chief prosecutor of the special task force for sex crimes against children and women. She created this task force in order to help the victims efficiently. She has investigated the sexual harassment and torture case of police superintendent Jo Gap-soo 20 years ago, but was not able to punish and arrest him due to a lack of evidence. After 20 years, she is still fighting this case against Jo Gap-soo’s law firm at the court.

What exactly is Ma Yi-deum’s secret that causes Yeo Jin-wook to change his mind about her and decides to work together with her as a team solving crime cases amicably and with chemistry?

Did they fall in love with each other in the end?

Did the two of them, together with Jo Gap-soo, managed to punish Jo Gap-soo for the sexual torture that he has done 20 years ago to his victims then?