Based on the short story "The Hanging Stranger".
Contains small references to other episodes: Philbert, who is commuting to work by train, is one of last few workers in Autofac, automated cars from Safe and Sound are visible, global warming and rising of oceans is mentioned in TV and the Candidate talks about planetary colonization and search for alien life forms.
The building used for the main characters apartment is actually offices on the university of Illinois at Chicago's East campus. The American film Stranger Than Fiction (2006) also uses the same location.
The basement pool scene near the end of the episode includes a number of Chicago artifacts, including an unusual ukulele above the screen. This ukulele is called a Polk-a-lay-lee and was sold by the Chicago based Polk Bros furniture store in the 1960s.