Yunqing is the concubine of the Hou family. Her biological mother died young. She learned weird medical skills and poison-making skills from a hidden poison doctor since she was a child. In order to cling to the powerful, the Hou family gave her to Xiao Yan, the king of Zhenbei who was on the verge of death from poisoning. The records in the fragments in the object were consistent, and the "heart blood" required for detoxification came from a close relative; she concealed her identity and secretly traced the cause of her mother's death, only to find that the Jiuyou Corroded Bones were made by her mother back then, and behind Xiao Yan's poisoning was an old case involving the late emperor, the harem, and frontier military power; Xiao Yan went from being wary of Yun Qing to relying on him. The two gradually fell in love with each other through suspicion and cooperation, but the detoxification had to be at the cost of Yunqing's own life. During the investigation, Yunqing encountered assassinations from his concubine, pressure from his aunt, and threats from mysterious palace people. At the same time, Xiao Yan's trust was provoked by a third party. Yunqing decided to use herself as a drug guide, but during the detoxification process, it was unexpectedly revealed that she was the orphan of the late emperor who had been exchanged. Princess, and Xiao Yan's poison was originally set by the old princelings to avenge her father; in the end, the truth was revealed, and Yun Qing used a newly developed method to eliminate the poison, but Xiao Yan lost all her power, so she chose to give up her throne and live in seclusion with him, completing her transformation from a chess piece to a chess player; the story combines house fighting, murderous pursuit, machinations and affectionate pull, and the rhythm is relaxed and moderate.
