Bai Xiao Jun suddenly loses contact with his fiancée. His last clue is a building in the shape of a dilapidated tube, where the woman was last seen. Wanting to find her, Xiao Jun takes the risk and decides to move there. On his journey, he meets a woman named Suo La, who decides to help him with his mission. But after entering the building, they both discover that this place hides many secrets, that its inhabitants have a lot to hide, and that they are not happy at all with the appearance of the two snooping intruders. But what are they really hiding, and how does it connect to missing women?