Set during the chaotic period of the Ming-Qing dynasty transition, Tae Yul, the best swordsman in Joseon, lives in seclusion with his daughter Tae Ok in the mountains after failing to protect and preventing the downfall of Gwanghaegun of Joseon. As Tae Yul's eyesight begins to fail due to an old injury, Tae Ok seeks to find a treatment for him. When she is captured and taken away by the slave trader Gurutai, Tae Yul is forced to raise his sword again in order to save her.