During the tumultuous reign of King Injo (1623-1649) of Joseon-era Korea, Chil-woo witnesses the brutal murder of his family and village at the hands of the government. As an adult, Chil-woo joins the Uigeumbu, a governmental body in charge of investigating injustices. But when tragedy visits his life once again, he becomes an avenger, hunting down those who have wronged the innocent.