Why The Silos Were Built In Apple TV’s Silo

Published Aug 21, 2026, 6:30 AM EDT

Dhruv is a Lead Writer in Screen Rant's New TV division. He has been consistently contributing to the website for over two years and has written thousands of articles covering streaming trends, movie/TV analysis, and pop culture breakdowns.
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Major spoilers ahead for Silo season 3, episode 8.For almost three whole seasons, Apple TV's Silo has maintained an air of mystery surrounding why the titular structures were built. On the surface, their purpose was known from the beginning: they protect the survivors from the toxic world outside. However, beyond that, little was known about what ended the world and why and how the silos were built to sustain humanity.

In its past timeline, Silo season 3 establishes that, long before the world ended, a massive global conspiracy was at play. Congressman Robert Keene soon got embroiled in it with a journalist named Helen after his sister, Charlotte, barely survived a dangerous US Navy mission over Iran.

After a series of events, Charlotte, Robert, and Helen find themselves having dinner with Senator Thurman, tech billionaire Stensen, and a few selected guests to discuss the Silo Project in season 3's episode 8. This is when the Apple TV sci-fi show hints at what might have happened to the world and why the silos were built in the first place.

The Silos Were Built To Survive A Potential Apocalyptic Nano-Tech Threat

Image courtesy of Apple TV

The tech billionaire, Stensen, opens up about how he has been a pioneer in the development of nanotechnology. However, what starts as a conversation about tech development in the US soon turns into a dark revelation about the imminent threat from nanobots. Stensen discloses that a global nano race is in full swing and nations like Iran are even attempting to exploit the technology.

Tracing back to the "dirty bomb" that was reportedly dropped on Washington, DC, Stensen and Thurman explain that it was actually a nano-weapon attack from Iran. Owing to the growing threat from nano-weapons and how easily they could end up in the wrong hands, Stensen, Thurman, and other powerful people expect an imminent apocalypse.

They realized that the global nano race was starting to get out of hand because developing destructive nano-weapons was far cheaper than nuclear ones. To prepare themselves for the potential world-ending event and sustain humanity, they built all the silos. The silos were built to accommodate hundreds of selected humans who would live down there until the planet could be safely repopulated.

However, given how Charlotte and her fellow US Navy pilots were lied to about their mission in Iran and deceptively sent on a sacrificial mission to secretly destroy Iran's nano weapons, it is hard to trust people like Thurman and Stensen.

Is Senator Thurman Honest About The Silo Project?

Rekha Garton/©Apple TV/Courtesy Everett Collection

If the silos were purely meant for eventual repopulation of the planet, it makes little sense that full-fledged Safeguard procedures have been installed in all of them to wipe out entire populations. Why would the silos' creators have protocols to kill hundreds of people when the final goal was to sustain humanity? Even the development of memory-wiping drugs raises many questions about their intentions.

They claim they want to sustain humanity and its history, which is why they promise to store knowledge, culture, and records of the old world along with seeds. But if they really wish to preserve humanity and its past, why would drugging entire silos be a part of their protocol? Also, Stensen is portrayed as a remorseless tech billionaire who cares little about the masses.

He throws his money around in Silo season 3's episode 8 and acts like he is some kind of savior of humanity. If it wasn't for his unchecked ambition, the world would have been safe from the growing nano conflicts. Even Thurman seems morally compromised as she is on Stensen's side.

All these developments and clues in Silo suggest there is more to the story than meets the eye, and the forces behind the silos had something else in mind when they first built them.

Silo

9/10

In a dystopian future, men and women reside in a vast underground silo governed by strict regulations, believed to shield them from the hazardous world above. The series delves into the complex social order within the silo and the mysteries surrounding their subterranean existence.