Modern truck driver Yue Junqing travels through time after a car accident and arrives in the Great Feng Dynasty, where famine has struck year after year. He becomes a man named Dalang who sells flatbreads, with a truckload of potatoes coming along with him. Using Tang poetry, he impresses a renowned scholar at the academy and earns a recommendation for a position at the county government. He improves cement to reinforce city walls, introduces potatoes that yield far more per acre than wheat, tests firearms at the military training grounds, and travels to the border to strengthen the defenses. He promotes high-yield crops in neighboring counties and defeats grain merchants and landlords who monopolize seeds. His achievements shake the imperial court, and he is summoned to the capital. After passing practical assessments and disaster-relief trials, he reunites with Huaiyu, the empress who is secretly investigating a case in disguise. Refusing to exaggerate his achievements or put civilians and soldiers at risk, he eventually earns the emperor's trust and is entrusted with construction projects, crop promotion, and disaster relief, helping the people suffer less from hunger.