"The Dark River" is the most mysterious assassin organization in the martial arts world, consisting of the Su, Xie, and Mu families, with the leaders of the three families collectively referred to as the Grand Elders. The Grand Elders are currently in critical condition due to a strange poison, putting their lives at risk. Upon hearing this news, the forces of the three families within the Dark River seize the opportunity to launch a rebellion. Su Muyu, the leader of the Grand Elder's guard unit, Spider Shadow, seeks the help of the divine healer Bai Hehuai from the Medicine King Valley to treat the Grand Elders while also fending off attacks from assassins sent by the other families to protect the Grand Elders.
