Suspicious cavalry suddenly appears outside a border fortress. The commanding general senses something unusual about the enemy's movements and suspects that an ambush outside the city is conspiring with an inside agent. Alongside her deputy general and strategist, she investigates military provisions and entry and exit records, gradually uncovering evidence that someone has been secretly diverting supplies and colluding with foreign enemies in an attempt to seize power amid the chaos. Facing layers of deception and a sudden rebellion, the general calmly organizes defenses and investigates in secret, joining forces with her soldiers to protect the city gates and its people. When the conspiracy is exposed, the rebels launch an attack. She leads her personal guards into battle, persuades the deceived soldiers to surrender, and ultimately captures the traitorous commander and puts down the internal rebellion. Peace finally returns to the frontier.