A Chinese Department of Health junior clerk Su Zhenghuai is with his eldest daughter Su Wei and son Su Yuexuan are on their way to visit relatives in the provincial city when they meet the long-lost second daughter Su Ling. Unfortunately, the train is attacked by rats. Su Yuexuan is bitten by a rat and goes into a coma. In order to save his young son and many bitten passengers, Su Zhenghuai and Su Wei decide to make the dangerous venture to Xiaobaihe Hospital to get medicine.

Fang Zhen Dong is a patrolling officer in Beijing who one night meets the drunk Li Pei Ru while singing karaoke at the KTV place. Li Pei Ru is a real estate agent from Hong Kong who has vowed to make her fortune in the cosmoplitan Beijing, but is caught up in the complexities of life and ends up becoming a mistress of a married man.

Pan Mengdie is the last “Xiguan Lady” of Guangzhou — once a legendary beauty, now the solitary guardian of a historic ancestral mansion in the Xiguan district. For nearly a century, she has fiercely protected her love, her family’s secrets, and the legacy bound to the old house that defines her life. Ma Sipeng, a brave and quick-witted community police officer, is assigned to a drug investigation codenamed “Xiguan Lady.” During the case, he becomes connected to Pan Mengdie and her descendant, Ye Yixi. As the investigation deepens, long-buried truths are uncovered, drawing all involved into a tense and emotional confrontation where law and humanity, family loyalty and blood ties, past and present collide — with lives hanging in the balance.