The peerless swordsmith, Meng Yezi, suffered the calamity of family extermination from the traitor Zhao Han served in the court for casting the famous Hanguang Sword. He desperately saved his son Meng Yang and left him the unforged Chengying Sword. Twenty years later, Meng Yang grew up and tried to avenge his father. At that time, Chengying Sword had not been cast yet to compete with Hanguang Sword. Then, the emperor was dying, and by chance, Meng Yang was assigned to escort the prince Gong Zidu back to the palace to succeed to the throne. Meng Yang accepted the task to investigate the truth about his family extermination for avenge. However, he met a fatal disaster on the way....