In the Yuan Dynasty (which has nothing to do with the Yuan Dynasty in the history books) during the Jiayou period, Emperor Su died suddenly of an incurable disease. The prince succeeded him, implemented reforms, and made politics clear and clear. All the four young masters entered the court as officials. Assisting the crown prince, the good times did not last long. The northern barbarians united with the border minorities to launch a massive invasion. Japanese pirates from the east and foreigners from the south coveted the vast land and resources of the Yuan Dynasty. There was corruption in the court and the power of the national division. Let's see how the four young masters saved them and how they fell into crisis.