An assassin named Tae-goo is offered a chance to switch sides with his rival Bukseong gang, headed by Chairman Doh. Tae-goo rejects the offer that results in the murder of his sister and niece. In revenge, Tae-goo brutally kills Chairman Doh and his men and flees to Jeju Island where he meets Jae-yeon, a terminally ill woman. Though, the henchman of the Bukseong gang, Executive Ma is mercilessly hunting Tae-goo to take revenge.
Si-hyun who lost all memory after a car accident and has colored hearing in which she can see sounds in colors, tries to complete the melody in her dreams. As the song nears completion, Si-hyun's fragmented memories return to her.
On May 9th, a female high school student was brutally murdered. There are 7 suspects and 7 shadows that terrorize them. Who are they and which one of them is you?
Coming to grips with the truth that he will never earn a living playing baduk, a young man's chance encounter with a local gangster finds him with a new pupil in this drama about the vastly different past and future of the two men.
Inspired by the true story of Kim Kyung-ho, a math professor who was arrested for shooting a crossbow at the presiding judge of his appeal against unfair dismissal.