These stories are usually set under Earth’s surface to varying degrees. Occasionally, a story might simply have characters who talk about the possibility.
“Vindica” by Ann Christy
Gordon is cleaning up after another survival party, celebrating sixty days since the doors were closed. He and a few others are responsible for doing all the work at the underground residence, having not paid their full fees before the zombie outbreak. He gets a call from Paul, the organizer of the establishment, to come clean up another mess. Gordon fumes over his situation, but tries not to let on.
This story can be read in the preview of The Z Chronicles. (24% in)
“Dark, Dark Were the Tunnels” by George R. R. Martin
Greel is in the tunnels, farther than anyone has been in generations. He’s a scout for the People. The taletellers say the People came from these tunnels. Ahead, the tunnels are on fire. Greel’s eyes hurt. When he touched some of the fire, it wasn’t hot. He’s unsure now what it is. His mind-brother, H’ssig, is nearby. He reaches out to him for assistance.
“The Underground Gardens” by T. Coraghessan Boyle
Baldasare Forestiere is a thirty-two-year-old Italian American immigrant living on seventy acres of California land. He tries to grow his own vineyard, but the land isn’t fertile. He works for other people to make some money, and starts digging more rooms in his underground home. He eventually meets Ariadne, giving him a new goal—to get her to marry him.
“The Man Who Lived Underground” by Richard Wright
An unnamed man is hiding from the police. In his desperate state he lifts a manhole cover and, despite the rushing water below, jumps in. He explores the tunnels and thinks about his options.
This story is a novella.
“Cistern” by Ray Bradbury
Juliet and Anna, sisters, sit inside on a rainy afternoon. While Juliet embroiders, Anna looks out the window. She starts thinking about the city’s drainage system with all its underground cisterns. She thinks it would be fun to live in one. She thinks about a man and a woman down there who are in love. She talks on about the possibilities to her sister’s chagrin.
“I Have No Mouth, and I Must Scream” by Harlan Ellison
There are only five humans left alive—four men and one woman. They’re being held in a underground complex by AM, a supercomputer. It makes life miserable for the group, but won’t allow them to die. They haven’t been provided with any food for days. One of the men hallucinates about canned goods in the ice caverns. They suspect AM is merely playing a cruel trick on them. In their desperation, they set out for the caverns.
“The Machine Stops” by E. M. Forster
Most humans live below the surface of the Earth, communicating with each other through video screens and rarely going anywhere. A machine takes care of everything for them. Vashti and Kuno, mother and son, live apart and have different views of their society – she is content while he is dissatisfied. He once visited the surface without permission. Soon, some new rules are instituted.
Read “The Machine Stops” (Novelette)