During the chaotic transition of the Ming-Qing dynasty, Tae Yul, the best swordsman in Joseon, lives in isolation with Tae Ok’s daughter in the mountains, after failing to protect and prevent the fall of Gwanghaegun from Joseon. As Tae Yul’s vision begins to weaken due to an old wound, Tae Ok seeks to find a cure for him. When she is captured and taken by the slave trader Gurutai, Tae Yul is forced to raise her sword again to save her.