Jiang Yan, a modern construction engineer, transmigrates to Great Xia and becomes a laborer forced to repair the city walls. Using his supernatural eyes, he predicts collapses, discovers water sources, and exposes inferior stone materials, rising from a lowly laborer to an assistant construction supervisor. He leads a group into the barren mountains, where they discover an iron mine. He then uses gunpowder to blow up the mountains and annihilate an army of 300,000 Northern Barbarians. Along the way, he brings down the corrupt and murderous supervisor Li, exposes the Fourth Prince's conspiracy to collude with the enemy and betray the country, and earns the Third Prince's trust and recognition. An elderly stonemason heroically sacrifices his life to ignite the gunpowder, becoming the guiding belief Jiang Yan holds onto. Ultimately, Jiang Yan is appointed Vice Minister of Works. One year later, after the new emperor ascends the throne, Jiang Yan is entrusted with overseeing the Grand Canal and Yellow River projects, continuing to serve his country through engineering and technology.