When Dayuan Emperor Li Chengyuan was reading memorials, he was swept into a modern film studio by a strange light from the imperial desk. Concealing his identity, he auditions for the film 'The History of Dayuan's Fall' in the crew, personally enacting his own ending of national ruin. With the desk fragment, open fire, and leaning close, he is able to travel back and forth between the two realms, but the fragment grows thinner with each transit. In modern times, he bitterly studies agriculture, smelting, railways, and water conservancy techniques, returning to Dayuan to implement pilot projects, improve farming, forge iron rails and hand-cranked carts, and construct dikes. When hostile border states invade, new grain, new machinery, and rail transport help Dayuan repel the enemy and negotiate peace. Years later, the country is prosperous and at peace, and nations pay tribute. Li Chengyuan locks the nearly shattered fragment into the imperial box, guarding his homeland forever.