During the Spring and Autumn Period, the states of Qin and Jin form an alliance by marriage. Duke Wen of Jin marries the daughter of Duke Mu of Qin. After Duke Wen dies, he is succeeded by Duke Xiang. To seek hegemony, Duke Mu of Qin sends Generals Meng , Bai and Xi on an expedition against the state of Zheng over the territory of Jin. Knowing that the expedition is bound to fail, one of the general’s fathers, Jian Shu, warns his son Bai to be vigilant when crossing Mount Yao.
Learning that Qin is about to invade Zheng, a merchant from Zheng offers twelve cattle to the Qin troops in the name of the Duke. Now that Zheng has been alerted, Meng changes the plan; instead of invading Zheng, he overthrows the state of Hua and then withdraws his troops. Expecting the Qin troops to pass over Mount Xiao on their return journey, Jin Marshal Xian ambushes the troops, capturing the three Qin generals.
Troubled by the hostility between Qin and Jin, Duke Xiang’smother pleads to her son to release the three generals. Learning that the duke has already granted release to the three generals, Xian pursues them, but all three generals have already been rescued by a boat sent by Jian Shu.