In 9th century China, during the Tang Dynasty, a trained female assassin named Nie Yinniang is sent back to her hometown on a mission to kill her cousin Tian Ji'an, a powerful military governor. Her mentor and master, Jiaxin, tasks her with eliminating him to test her allegiance to the order she serves. However, upon returning home, Nie grapples with the emotional ties that bind her to her past and her lingering affection for Tian, whom she was once promised to marry. The conflict between duty and heartfelt emotions creates an inner turmoil that complicates her mission.

As Nie navigates the politics and power struggles of the Weibo province, she finds herself torn between completing her mission and following her own moral compass. She must decide if she will remain loyal to her master’s teachings or protect those she cares about. Throughout this journey, she faces various threats and challenges that put her skill and resolve to the test. The story artfully explores themes of loyalty, love, destiny, and the personal cost of rigid obedience to duty, all set against a backdrop of stunning landscapes and intricate period detail.