In search of his missing sister Shen Zhiyi, programmer Shen Mo accidentally moves into Yong'an Apartment, only to discover that this old building hides a secret - behind the thirteen strange house rules are the ghosts of seven construction workers who were sealed into the building in 1998.
Here, Shen Mo met former criminal police officer Lu Zhixing and nurse Bai Lu, and the three formed an investigation team to uncover the truth of the code step by step: Each of the seven workers had "unfulfilled wishes" and only by helping them fulfill their obsessions could the seal be lifted.
As the investigation deepens, deeper secrets emerge—eleven victims of the 1973 textile factory boiler explosion are still buried under the foundation of the building, as well as a young inspector Jiang Yun who took the initiative to seal himself underground. Shen Mo's sister Shen Zhiyi has turned into the "system administrator" of Room 404, guarding the order of the building with codes.
The arrival of the demolition order broke the brief calm. Faced with the threat of forced demolition by developers, the protagonists united the residents of the whole building and all parties to finally make Yongan Apartment a protected industrial heritage. The undead in the underground finally got a call they had been waiting for for fifty years - someone read their names and they could get off work.
As the story ends, the door of Yongan Apartment is always open: whoever is hungry can knock on the door. It doesn't matter how many times you knock it. Someone will definitely open it. **
