Su Xianling (played by Zhu Lilan) is an extremely skilled assassin. Although her assassin skills are extremely outstanding, she has never really participated in an actual assassin mission.In order to realize her dream of becoming the number one assassin in the world, she decided to take the initiative and accept various challenges.In the process of protecting her fellow disciples, she was entrusted with an important task and took on an unfinished assassination order.However, an accident occurred during the mission, and she almost killed Dongfangjing (played by Li Ruotian).Dongfangjing is the city lord. Although he is the city lord on the surface, there are murderous intents in his mansion, and even his mother is eyeing him.In order to protect himself, he had to pretend to be stupid and hide his true intentions.The insurance policy he had set for himself was mistakenly considered by Su Xianling as an assassination order, which almost killed him.At this critical moment, Dongfang Jing cleverly used Su Xianling's identity as a cover to secretly search for the elite troops left by the late emperor to resist the invasion of the enemy forces of the Empress Dowager.In the process, they unexpectedly unveiled a long-closed history.Su Xianling, a female assassin with great martial arts skills but simple and reckless skills, unexpectedly sparks of love burst out between the city lord Dongfangjing, who is full of pain and hatred.Their relationship has undergone complex changes in the transition from killing to protection, and the relationship between the two continues to heat up.