Chen Yan is a well-known master of solving crimes in the police station, but due to a bizarre "Red Dress Jumping from a Building Case", he accidentally activated the ancestral "Yin Yang Case File" golden finger - which can see through the disguise of evil spirits and open a space door to infinite dimensions.
During the investigation, he met Su Ye, a cold and mysterious nun who was powerful but hid a secret. The two were forced to team up and go through weird dimensions such as "Folklore Ghost Village", "Evil Hospital" and "Ghost Playground" to solve a series of inter-dimensional murder cases.
But he didn't expect that the "teammates" around him were actually related to the case he was wrongly convicted of back then, and the man behind the scenes was actually his once-trusted "green tea" colleague, a heartless boss, and a cunning evil cultivator who manipulated dimensions!
The positions of good and evil are at odds, but love quietly grows. When Su Ye's identity is changed, Chen Yan's golden finger reveals a bigger secret. In the infinite space, the two of them have to solve the case and pursue the murderer, fight against the evil spirits across dimensions, and struggle between love and hate - "So what if you are a ghost? I can solve human cases, and I can even protect you, a female ghost."
