Architect Olivia and computer game developer Tim are going through a difficult period in their relationship, and the woman decides to break up. As she packs her things and opens the front door, Olivia is greeted by a dark brick wall instead of the hallway of their apartment building. The wall bounces metal objects off of itself and is particularly strong, but the couple has heavy tools at home to break through the slabs and ordinary walls to their neighbors. They soon learn that the wall surrounds the entire house. To get out, the couple now has to cooperate with the neighbors who are also trapped.