Engineer Fang Yuan woke up and became the last king of the Xia Dynasty, which was about to be destroyed. Enemy troops invaded the country, courtiers rebelled, and the treasury was empty. Even the system judged that he would not live for three days. But the blast furnace he had built in his previous life, the molten steel he had rolled, and the stress formula he had calculated were the most powerful cheats in this world where iron tools were considered rare. From the shock of the first furnace of molten steel, to the plate armored infantry crushing the cavalry, to the black powder blowing open the city gates, he would use drawings and forging hammers to tell this era: the so-called king's hegemony is just a calculation problem written by an engineer. And when the blast furnaces on the border erupted from the first wisp of black smoke, he would decide the rules of this world from now on.
