Fallout Show: Vault 32 Experiment Explained - What Happened?

By Klein Felt Posted:
Fallout Vault 32, Lucy

The experiment hiding within Fallout's Vault 32 was a shock to fans, showcasing some of the series' darkest storytelling. 

Amazon Prime Video's take on the beloved Bethesda video game franchise offered fans a new look at the series' iconic underground vaults. 

While the in-universe corporation Vault-Tec publicly sold these vaults as fallout shelters for those willing to pay top dollar, it has since been revealed that each post-nuclear community was meant to house an experiment, some of which were more nefarious than others. 

What Was Happening in Fallout's Vault 32?

Dave Register as Chet and Moisés Arias as Norm in Vault 32 looking at dead corn in Fallout on Amazon Prime Video
Amazon Prime Video

One of the vaults showcased in Amazon Prime Video's Fallout series featured a deadly experiment that is macabre even for Fallout

Vault 32, the neighboring community to Lucy's (played by Ella Purnell) Vault 33, has a dark secret uncovered slowly throughout the streaming series' first season. 

After raiders make their way through Vault 32 and launch an attack on Vault 33, the members of Lucy's community assume it was their invaders who also killed the residents of their underground next-door neighbors.

However, there was so much more going on. 

In Episode 4, following a few visits by Moisés Arias' Norm, Norm and fellow vault dweller Chet (played by Dave Register) discover all the residents of Vault 32 were seemingly killed by each other and not by some external force. 

They then learn Vault 32 was home to a skin-crawling experiment that saw the residents likely eat one another. 

A Vault 32 TV explaining the mouse utopia experiment in Fallout on Amazon Prime Video
Amazon Prime Video

When they happen upon a TV explaining the purpose of Vault 32, the pair discover that this shelter is home to a "mouse utopia."

A mouse utopia, as described in the show, is a set experiment that gives its subjects "all the amenities, all the food they can eat, [and] all the padding they can sleep on" before overpopulation takes hold and what is known as a behavioral sink starts to occur. This causes a desperate fight to begin for the "once endless space" resulting in the subjects eating each other:

"This rodent colony is called a mouse utopia. Inside, the mice enjoy all the amenities, all the food they can eat, all the padding they can sleep on, but eventually overpopulation occurs. The mice fight for the once bountiful foo, the once endless space. They eat each other in their desperation to survive."

While it is not expressly revealed that a mouse utopia was what was happening in Vault 32, following the revelation that Vault-Tec was using the vaults for various experiments later in the series, it is heavily implied that Vault 32 was home to a human take on a behavioral sink. 

Two vault dwellers with a flashlight exploring a dimly lit Vault 32 in Amazon Prime Video's Fallout
Amazon Prime Video

Several members of the scientific community carried out these sorts of experiments with mice in the mid-20th century. 

Most prominently, ethologist John B. Calhoun studied the effect of a mouse utopia, coining the term behavioral sink to reflect the dissent in society due to overpopulation. 

This Vault 32 experiment is just one of many found in Fallout's myriad of underground nuclear shelters (read more about other Fallout vault experiments here). 

Fallout Season 1 is streaming now on Amazon Prime Video. 

Read more about Amazon Prime Video's Fallout series:

Fallout: How Old Is Lucy, Maximus, Ghoul & All Main Characters (Ages Explained)

Fallout Show: How Did Moldaver Survive?

Full Cast of Fallout Episode 2 - Every Main Character & Actor Who Appears (Photos)

Matt Berry's Multiple Fallout Show Roles Revealed

- In This Article: Fallout
Release Date
April 10, 2024
Ella Purnell
Walton Goggins
- About The Author: Klein Felt
Klein Felt is a Senior Editor at The Direct. Joining the website back in 2020, he helped jumpstart video game content on The Direct. Klein plays a vital role as a part of the site's content team, demonstrating expertise in all things PlayStation, Marvel, and the greater entertainment industry.