The politically persecuted Marshal Sun Chuanting (Leon Dai) is released from prison and ordered by Chongzhen Emperor (Yu Shaoqun) to defeat the rebels with only 5,000 troops.

Arriving in Tongguan with his wife (Feng Bo) and child, he is greeted by the corrupt garrison-commander He Renlong, who does not know that Sun has come to execute him and his men for their dereliction of duty.

Meanwhile, the itinerant physician Wu Youke (Feng Yuanzheng) is put on trial for allegedly poisoning a patient with his unconventional treatments.

Wu decides to visit his former teacher in Tongguan, but is forced by Ming troops to attend to the wounds of Li Tianyou (Sun Qiang), a disillusioned scholar who contemplated joining the rebellion.

When Sun attempts to confiscate public lands stolen from the local garrison by the gentries, they bribe his deputy Ren Qi (Hu Xiaoguang) to burn down the government archive storing the evidence.