During the Northern Dynasty, Hei Mulan joined the army for her father, and returned with honor. Ten years later, Zhuzhzhan violated the border again, and Mulan resolutely returned to the battlefield. To save Toba, Mulan fell to the enemies. In prison, Mulan saw through Kun Peng’s tricks. Kun Peng killed Han and blamed her. Mulan protected innocent people, after the princess pointed out that the real killer was Kun Peng.