During the turbulent mid-Tang dynasty after the An-Shi Rebellion, Baiyu Jing was established to protect the imperial city from warlord threats. Externally, it shelters homeless women, while internally, it trains female assassins known as "Yinniang." These women navigate life amidst danger, facing trials of love, betrayal, and their fates. Ultimately, they find themselves caught in a growing conspiracy, leading them to rise and fight in defense of the world and its people.