A low-ranking soldier, Zhou Qi, is falsely accused and sent to the border army's penal battalion. After eliminating the wicked Wang Mazi according to military regulations, he is promoted for his achievements and takes Gu Yilan to guard the dangerous beacon tower at Ghost-Sorrow Gorge. He annihilates the Sky Wolf scouts despite being outnumbered and defeats their elite cavalry with ingenious traps. He then persuades the displaced armed forces of Black Cloud Stronghold to surrender, wins over Lin Hongxiu, and leads twenty light cavalrymen in a surprise raid on the Wolf King's camp. By seizing the royal banner and golden seal, he forces the southern army to retreat in panic. Rising against the odds from a condemned prisoner in the penal camp, he slays enemy commanders, deftly overcomes obstacles within the army, and forges a legendary path of defending the frontier and protecting the nation amid chaotic times.