The drama tells the story of Ye Chong (Allen Ren), a secret agent of the Communist Party who goes by the name “Autumn Cicada”. In 1941, he poses as a Japanese officer stationed in Hong Kong to stop the conspiracy of the Japanese while trying to accomplish a top secret mission he has been given.
Set during the Republican era. Dong Fang Jing Qi (Janine Chang) was brought up by her foster father who taught her about medicine. Before he dies, he tells her about the family’s enemy. To get revenge, she starts working as a maid in druggist Du Yuan Shan’s home. However, when she’s about to reach her goal, Du Yuan Shan tells her the truth about the events back then. In the meanwhile, Du Yuan Shan’s son Du Ming Hai (Liu Huan) develops feelings for Jing Qi.