Modern senior mechanical engineer Jin Feng died of overwork and time-traveled to the DaKang Dynasty. Pressured by the imperial court to marry, he married Guan Xiaorou, who was regarded as a jinx. Relying on modern knowledge, he built strong crossbows for hunting to survive, improved the spinning wheel to start a textile workshop, gathered neighbors, and befriended Marquis Qing Huai from a military family. Facing the threat of mountain bandits, Jin Feng used his resourcefulness to eliminate local hidden dangers. Invited by Qing Huai to head to the border, he skillfully utilized tactics such as horse-trap pits and new square formations, heavily defeating the Dangxiang elite cavalry in Qingshui Valley and making great military contributions. However, amidst court intrigues, Jin Feng only received an empty baron title.