In her previous life, Shen Yanqiu, daughter of the General of Zhenbei, was betrayed by her younger sister, Shen Mingzhu, and her fiance, Prince Jin. She died with hatred in her heart after plunging from a cliff. Reborn at the age of fifteen, she discovers that she is a rare human-demon hybrid, with the bloodline of the Demon King flowing through her veins and a duty to protect the balance between the human and demon realms. Meanwhile, Xie Chengyu, a powerful official who appears as gentle as jade, is actually a descendant of a reclusive demon-hunting clan, secretly investigating a shocking conspiracy that spans both realms.
By day, Shen Yanqiu is a noble young lady of the marquis's household, joining forces with Xie Chengyu to outmaneuver their opponents in the court's power struggles. By night, she becomes Qingluan, guardian of the demon market, and clashes with Xie Chengyu, who takes on the identity of a Celestial Master. During their investigation, they discover that the betrayal in her previous life is entangled with demon-clan infighting and human political rivalries. The mastermind is bent on igniting a war between humans and demons to attain eternal life.
As they struggle to keep their double lives from tearing them apart, Shen Yanqiu and Xie Chengyu go from opposition to trust, and from using each other to falling deeply in love. When the truth comes to light, they must face the demon clan's prejudice in favor of "pure blood" and withstand the relentless pressure of powerful human officials. In the end, they risk their lives and shed blood to bridge the divide between the two realms. Reborn amid the flames of war, they forge a love of redemption that transcends both race and hatred.
