Chen Jin, 32 years old, is a former trace analyst of the Criminal Investigation Detachment. He was falsely accused and suspended due to a bizarre murder case that resulted in the tragic death of his partner. He has made a living by performing plastic surgery on corpses in funeral parlors for three years. He has a cold and taciturn personality, meticulous logic, and has a calm perception of death that is different from ordinary people. On a rainy night, while handling the body of an unknown woman, he discovered that her chest was engraved with the same symbol that his partner had left before his death - a twisted "door".
That night, he fell into a coma with a high fever. In his dream, he was pulled into an "upside-down city" filled with gray fog. A remnant soul who called himself the "Gatekeeper" stuffed a bronze pocket watch into his palm: "You have been marked, and you will either become a lamp holder or become a wandering ghost."
