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.