Lin Anping, the son of the guilty minister, pretended to be crazy and worked as a fool for three years to save his life. After the tragic death of his loyal servant and his fiancée Xu Shiyao's public breakup of the engagement, he completely awakened and defected to Beiguan under an assumed name. With his unparalleled ingenuity, he captured the prince of Beihan alive with an outnumbered enemy, defeated three cities in a row, and was granted the title of Marquis of Wu'an. After returning to Beijing, he took charge of the city patrol department, killing enemies on the streets, rectifying the powerful, and launched a fierce power struggle with the prince's party. Beihan committed another crime. Lin Anping saw through the prince's conspiracy to collude with foreign enemies, went deep into the grassland to sweep away the enemy, and finally defeated the main force of Beihan, and was granted the title of King of the North. He successfully rehabilitated the family, and even won the love of the seventh princess Song Yulong.
