During the investigation of a serial murder case, detective Lu Chen accidentally discovered that he could see the "underworld" - a parallel dimension that ordinary people cannot detect, a field of resentment condensed by the obsession of the deceased. When he found the third victim in an abandoned funeral home, the woman covered in pitch black said four words in his ear: "Hell is full."
From then on, Lu Chen was involved in a whirlpool from which he could not escape: there were unsolved cases in the world, and there was an out-of-control order in the underworld. He could neither warn the underworld nor be accommodated by the underworld. When the cases of suicides, disappearances, and mysterious deaths were connected together, he discovered that the murderer he was tracking was no longer human.
