Kim Ji-Su is a hotel housekeeper who can uncover guests’ secrets by reading the “stains of memory” left behind in their rooms. Using this ability, she runs a side business spying on guests’ private lives and blackmailing them. One day, while cleaning the room of a guest named Yeon-U, who had particularly caught her eye, she comes face to face with a memory she should never have seen. (Source: Naver, translated)