Lin Wan, a graduate student in folklore, accidentally inherited the ancestral "Yin Yang Book" and was able to see and record strange rules in the world. When she discovered that there was a "trick door" to the underworld hidden in the city, she resolutely chose to hand it over to the state. Based on this, the country established the "Paranormal Investigation Bureau". As the chief consultant, Lin Wan led the team to crack the Chinese horror rules one by one and protect the peace of the world.
