On a rainy night in Xuandu, the headless corpse of an abandoned factory lured Lu Zhao, the commander of the Xuanwei Division, into the situation, and also led him to meet Su Qinghuan, a cute medical apprentice from Nancheng Jishitang.
She is the "Little Doctor Su" who can perform muscle-activating magic with his fingertips. She is also an orphan of the Xuanyin Sect who has been dormant for ten years and uses corpses as bait. She plans a killing just to avenge her family's enemies. He is an evil-killer with a pure Yang sword, but during the investigation, he fell in love with this "harmless" girl until he discovered that all her gentleness was just a disguise.
The evil atmosphere in the Soul Refining Cauldron is getting stronger, and hatred and love are torn apart. When the truth was revealed, he held her sword to protect her against Quan Si, but she held the cauldron that sealed the evil power and hesitated: Should this rainy night mystery that started with lies end with revenge, or should it leave a trace of human warmth for him?
