Late Sui Dynasty: Rivers Finally Flow into the Sea

In the prosperous age of Zhenguan, rivers surged and eventually returned to the sea; a master craftsman used technology to create a legend for the country. Li Yan, a descendant of a down-and-out craftsman in the former Sui Dynasty, was burdened with Yu Wenkai's technical manuscripts and struggled to survive in the troubled times of the late Sui Dynasty. With his unique skills in water conservancy and city defense, he helped Li Shimin pacify the four sides, but he was trapped in the whirlpool of the battle for the reserve position. In the early years of Zhenguan, he refused to enter the court and went out to control floods and pacify the people in Shandong. He founded the Gewuyuan to break down class barriers and used technology to illuminate the path forward for poor families. After experiencing political turmoil and powerful obstruction, he finally fulfilled his original intention of "technical security for people's livelihood, education to build the world" throughout his life. When the Yellow River was calm and the people lived in peace, his figure turned into a monument on the embankment, and his ideas merged into the rivers and seas of the prosperous Tang Dynasty. The fire was passed down from generation to generation and spread throughout the world.