KIM Ho, once the finest swordsman in Joseon and a royal guard, finds himself reassigned to a prison where he is tasked with overseeing the inmates. One night, as he dozes off, a commotion erupts, and five armed individuals confront him. Their mission is to free LEE In-jua, who has been incarcerated for allegedly plotting a conspiracy. LEE In-jua, along with these five martial experts, intends to destabilize the nation once more. Ho is now compelled to battle this ruthless group, not just to fulfill his responsibilities, but also to protect his family.