Modern veterinarian Su Tang time-travels into a book, becoming the cannon-fodder legitimate daughter of the Zhenguo Duke, who is destined to die in a tiger's jaws. Her original family is framed by Noble Consort Shu and the Crown Prince, leading to their execution, so she hides as a maid in the mansion of the Third Prince, Xiao Jing. Su Tang can understand animal language and discovers that the white tiger pouncing on her has been poisoned with a venomous needle by someone. She steps in to treat it, earning Xiao Jing's appreciation. Using her animal-language ability to navigate among the powerful, she and Xiao Jing investigate the miscarriage of justice together, gradually developing mutual feelings. Enemies recognize her through a birthmark and repeatedly try to harm her, but animal warnings foil their attempts. In the end, the two clear the Duke's mansion of grievances, Xiao Jing ascends the throne, and Su Tang is made Empress.