During the later years of the Kangxi Emperor's rule, his many sons were vying for the throne. The fourth prince, aided by Lusi, Nian Gengyao, and Han Chong, while the fourteenth prince had the support of martial arts master Zeng Jing. The competition between the two became intense. Lusi developed a romantic relationship with the fourth prince while Zeng Jing also had feelings for her, making their situation more complicated. Later, the fourth prince killed Kangxi and altered the imperial edict, successfully usurping the throne and naming himself Emperor Yongzheng. From then on, Yongzheng ruthlessly eliminated dissidents and even betrayed those who helped him, causing Lusi to regret her involvement. Ultimately, the fourteenth prince plotted to assassinate Yongzheng with the help of Zeng Jing and Lusi, igniting a fierce battle.

The Red Flower Society infiltrates the Qing court, and Emperor Qianlong goes to Jiangnan disguised as a commoner, where he meets and takes in Kong Kong as a maid. They meet Fang Shiyu and are introduced to the leader of the Society, Han Tianchou. With the help of the White Browed Taoist and others, Han intends to overthrow the Qing dynasty, and Qianlong must investigate. Meanwhile, Muslim princess Ma Xianglei seeks Han's help to retrieve the Quran stolen by Qianlong. Xianglei and Qianlong develop mutual feelings, and so do Shiyu and Kong Kong, but they face many obstacles. Ultimately, Qianlong succeeds in dismantling the Society, but Xianglei is murdered. The culprit incites more conflict to harm Qianlong, who vows to avenge Xianglei by finding the true killer.