In Haicheng in 1935, undercurrents arose amid the prosperity of singing and dancing in the concession. Japanese forces infiltrated and the patriotic organization "Candle Dragon Society" was lurking in activities. Wen Yining, the doctor at Baicaotang, looks cool and taciturn and is good at acupuncture, but in fact he is a genius poison doctor code-named "White Fuzi". He saves people with his left hand and hides poisons with his right hand. He bears the pain of exterminating his family and seals his heart.
Shen Yanzhou, the president of the Chamber of Commerce who returned from studying in France, is a "ferryman" who is the core leader of the "Candle Dragon Society" under his suave appearance, and he has a paranoid desire for protection hidden in his strategizing. A strange illness at a banquet reunited the two. Shen Yanzhou recognized the woman who saved him on a rainy night three years ago from the unique poisonous fragrance, and used the medicinal materials as a guide to keep her by his side.
During the temptation and closeness, the poison technique became their code word, and their love grew in the poisonous fragrance. She uses poison as a blade to disrupt the enemy camp, and he uses Shang as a shield to protect her. The "Ice Poisonous Ink" conveys information, and the "Anshenxiang" hides worries. Faced with Sato's constant pressure and the traitor's betrayal and conspiracy, the two work together to break the situation with poison, use "child-mother poison" to fight back, and reveal their true nature in the flames of war.
