Unemployed young man {Lin Xia} accidentally joined Tongda Express and was assigned to a special area exclusive to the underworld - a weird express delivery with a delivery number starting with the word "ghost". The recipients of the incense candles from the Chenghuang Temple and the Mengpo soup ingredients from Naihe Bridge are all residents of the underworld, and the rewards are Yin notes that can be exchanged for real money. While delivering a "resurrection letter", {Lin Xia} met the ghost of the recently deceased actress Su Man, who claimed to have been murdered and the letter contained clues to the murderer. {Lin Xia}, who was haunted by the ghost, was forced to get involved in the investigation, and found out that the sender was Suman's agent - he embezzled public funds and forced Suman to death in an attempt to use the resurrection letter to control the ghost to cover up the crime. With the help of Suman Ghost, {Lin Xia} collected evidence and called the police, and the agent was finally arrested. In the end, {Lin Xia} quit her job as a courier and opened a small store called "Yin Yang Messenger" to deliver the unfulfilled wishes of both worlds.
