Whether it is day or night, there are always different types of men going in and out of this old building in Sham Shui Po. Clearly this is no ordinary building. The corridors are decorated with colorful neon lights. In front of every door, there stand a half-naked sexy woman. After all, it is the most famous red-light district in Hong Kong.
Li owns a few apartments in the building and she earns a living by renting them to the prostitutes. To the prostitutes though, she is more a friend than just a landlord.
However, this old building will soon be demolished as part of the urban renewal plan. Despite the constant harassment and threats from the triad, Li is not giving up on the apartments. She gets together a group of prostitutes and work as hard as they can to try turning the tide. Yet, they do not know they are quietly approaching death.
It begins with the missing of a prostitute, Ping. Ping is one of the tenants who lives with her young daughter. News of Ping’s disappearance disrupts the Chinese New Year dinner party of the building. Initially, they think it was the triad who has kidnapped Ping and want to resolve the problem privately.
In the process of finding Ping, however, more questions rises. Li discovers there have been a lot of missing prostitutes in this building, yet none of them are found. As the truth starts to unfold, more prostitutes are killed. The building is somehow isolated from the outside world and a massacre begins.
Over the night, Li and the prostitutes have to find Ping and fight a battle of wits against the invisible murderer. Li even suspects the murderer is among them.
As more evidence of the murderer’s identity discovered, a tragic truth hidden for over twenty years starts to unveil.