During the anti-revolutionary coup in 1927, Xia Heng Xuan dies while saving the Communist Party member Ren Zhi Yuan (Kevin Tan), and leaves behind her younger sister Xia Yu Zhu (Yang Zi Shan) and her maid Shuang Ju (Nikita Mao). While the delicate Yu Zhu tries to earn a living alone, Shuang Ju enters the Kuomintang’s special agent organization on the recommendation of Zhi Yuan’s lover Xiao Cheng Bi (Liu Min). A few years later, Yu Zhu saves Zhi Yuan by chance. After Zhi Yuan sacrifices his life, Yu Zhu is touched and decides to work for the Communist Party’s underground organization. There she gets to know Cheng Bi’s younger brother Xiao Jun Hao (Chen Xiao), who received the same mission. While they work together, feelings develop.