After a narrow escape from the assassin Helan Jie, Duan Ling and Wu Du race back to Tong Pass to carry out their mission: eliminate the treacherous general Bian Lingbai and take control of the fortress on behalf of Southern Chen's imperial court. Yet their task takes a perilous turn when enemy forces outside the pass, sensing weakness, seize the chance to launch an all-out attack. Duan Ling must use all his wits and everything he learned from his father to hold Tong Pass against the foreign invaders until help arrives.