Jian Qi has an ulterior talent since an accident when she was seven years old. She has a pair of eyes that can see ghosts and gods. There is another unspeakable secret, which is that she retains some memories of her previous life. Even though she doesn't want to have anything to do with these things at all! For this reason, she joined a group called an investigation agency and met the team leader's poisonous tongue son Park Chanyeol. He was not only enemies, but a poisonous tongue man who loved to stir up troubles, but he always had a tacit understanding with the talented Jian Qi. It is said to be an investigation agency, but it is different from what the general public thinks. Their job is mainly to take on some difficult cases that ordinary people cannot solve. In short, they are a group of officials who work for the underworld. One after another strange cases, the seemingly venomous but timid Park Chan-yeol, the mysterious Jian Qi and a group of friends, the mysterious and difficult Baekhyun, the ghost master Lu Han, the god of death Zhang Yixing, the great master Park Woo-jung, and the malt paste cousin Oh Se-hun, how to solve and discover the truth one by one.