Twenty years after the Hae clan, a family of masters of the world's greatest martial arts, the Unsasim method, was wiped out, Mak Gwan, the head of Dongbi Academy, a school dedicated to documenting and reporting on martial arts, disappeared after receiving an invitation. Mak Mun-gun heads to the Yongmun Inn on Sachwi Mountain, as specified in the invitation, to find his master.

Retired soldier Chen Shisan accepts a high-risk mission to escort the captured thief Su Huan to Baimagu Pass. As vengeful foes and bounty hunters launch relentless attacks, his nine-man team suffers heavy losses. Forced to rely on his veteran instincts, Chen Shisan must battle through deadly ambushes and keep his promise to see the mission through.