In the prosperous but hidden turbulent Zhaoyue Dynasty, the status of incense makers was respected, and incense makers had to pass the "Nine Incense Tests" to obtain official status. The once glorious Wenxue Pavilion in Bianjing fell into decline. The young master Yun Zhiyi has a disability in his right hand and struggles to make a living by mixing incense with his left hand.
In order to raise money to participate in the incense test, Yun Zhiyi accepted a commission from a brothel to "prepare love incense", but was involved in the assassination of an oiran, and the royal forbidden incense "Huan Zhong Huan" was discovered at the scene. The cold-faced prince Xie Wei, on the pretext of investigating the case, forced her to join the Diting Department and set a desperate situation of "solving the case in seven days or else she will be poisoned".
During the investigation, Yun Zhiyi relied on his special skills of being able to trace the scene of the murder through his sense of smell to detect bizarre cases one after another, but he also fell into the whirlpool of various forces. The Jianghu intelligence dealer Jiang Budu approaches in disguise, and the fate of the three people becomes entangled. As the case progresses, the shocking secrets of the identity of the orphan from the previous dynasty and the royal family's secret "Tianxiangpu" gradually come to light.
