In which episode did Prime Minister Xiao Shenyang explain his son?

In the fourteenth episode, Liu Yong pretended to be deaf and dumb when he went to court, but after he went to court, he erased all the words in Sikuquanshu. Qianlong was furious. As soon as he heard about the people, he went incognito. I found that no one dared to speak in the streets and lanes, and the signs on the streets were covered. Small Shenyang was detained in the street for saying "tomorrow" and came back after playing the board. There was no voice above the imperial court, and Qianlong finally found the situation serious. Liu Yong took this opportunity to participate in a copy of Wang Zhongzhi, a cabinet university student.