You never know whether the next person who smiles at you is an impostor wearing human skin. This is a terrifying world that later generations call the "Afterlife," also known as the "Backrooms." No one can identify the impostors hiding among the crowd, and there is nowhere for humanity to escape. All they can do is wait in the darkness for slaughter to begin. Fortunately, Lin Yang unexpectedly acquires the identity of a "Prophet," allowing him to verify one person's true identity each day or obtain a highly precious piece of survival intelligence. As despair engulfs every living being, Lin Yang relies on his reasonably sharp mind to painstakingly carve out a narrow path to survival for all those lost in this suffocating deadlock.