Unable to Sleep with Sinful Desires

(Strong and sultry detective x cool white and black female teacher) The place where people can't go is the ghost land, and the place where ghosts can't go is the human heart. A serial murder case on a rainy night involved a dark transaction that started ten years ago. "Yes, he is the murderer" "But this murderer died two years ago." As all the traps are being calculated, who is the hunter and who is the hunter? Ps: The male protagonist is a straight man with a steel mouth and a hard mouth