Soon Tae is a proud law-abiding citizen of Korea. One day, he is wrongly accused and arrested as the main suspect behind the murder of the daughter-in-law of a major conglomerate, DH Group. Despite Soon Tae’s pleads of innocence, he is sentenced to death, and his daughter is forced to endure the hardships of being all alone. Soon Tae, who lost all hope, sends out a letter of desperation to an idealpoliceman, Pil Jae.
However, Pil Jae now works as an illegal law broker at a law firm as he quits his job due to an ex-partners’ betrayal. When Pil Jae receives a letter from Soon Tae, he first disregards it, but as he finds out that the case is related to his ex-partner, he digs in for revenge. As Pil Jae tries to solve the murder case, he soon learns that the rabbit hole is deeper than he thought.