Gurus in the late Goryeo dynasty try to obtain a fabled, holy sword, and humans in 2022 hunt down an alien prisoner that is locked in a human's body. The two parties cross paths when a time-traveling portal opens up.

Tae-yeul, a swordsman in his thirties goes out to find his only daughter after losing one of his eyes. Min Seung-ho, the Joseon dynasty's best swordsman chooses an ordinary simple life after perceiving the transient nature of power. Gurutai, the best swordsman in Qing dynasty aspires to become the best even in the Joseon dynasty.