When Su Yuan woke up in a rental house in Qingchuan City, there was only a solid white outside the window. An anonymous text message told him to "go south and don't look back." He boarded an old driverless bus and was transported into a night-time city called "Fog City". Here, a bronze door plate hangs in front of each building, engraved with three seemingly absurd rules. There is only one way to survive - to find out the real way of survival hidden behind the rules before the clock strikes midnight.
Su Yuan suffers from prosopagnosia and cannot recognize faces, but he can see "emotional color blocks" floating above everyone's head. In Fog City, this flaw becomes its only advantage: monsters have no color.
The deeper truth is that Wucheng is not a city, but a mental prison that split apart after Su Yuan himself was in a coma for seven years. Every door sign is an unhealed wound deep in his heart. The process of passing the gate is suturing one's own soul.
