What to Know About the Books Behind Apple TV+’s Silo

“If you boil the pact down to one rule, it’s do not say you want to go outside, or you will go outside.”

According to Holston (David Oyelowo), the sheriff of the Silo in Apple TV+’s aptly-named new sci-fi series Silo, that’s the secret to staying alive in the mysterious subterranean city where he and his fellow community members exist: never get too curious about what’s going on in the world above.

Created and written by Graham Yost and directed by Morten Tyldum, the 10-episode post-apocalyptic drama is based on Hugh Howey’s bestselling novel series of the same name and is set in a dystopian future where the last ten thousand people on Earth live in a mile-deep underground silo, abiding by strict regulations they believe are in place to protect them from the toxic atmosphere outside.

“Life in the silo in many ways is pretty good. They’re part of this cause, which is basically just to stay alive until the day that it is safe to go outside. So they feel that they’ve got this common mission,” Yost told the Associated Press. “But you just get a sense that there’s been a slight eugenic program to try and breed out curiosity, independence, obstreperousness—all those nasty human things. And you also get the sense that that’s not going to succeed.”

The show’s first two episodes are set to premiere on May 5, with a new episode dropping every Friday through June 30. Rebecca Ferguson, Common, Harriet Walter, Chinaza Uche, Avi Nash, Rashida Jones, and Tim Robbins star alongside Oyelowo.

What to know about the Silo books

Howey’s trilogy of novels, Wool (2011), Shift (2013), and Dust (2013), originally started as a standalone short story titled “Wool” that Howey self-published in July 2011. Reviewer demand led Howey to release four more installments in the Wool saga over the next six months. The Wool novel combines these first five stories into a single volume. Shift includes stories six through eight, while Dust is the ninth and final chapter in the series.

The secrets of the Silo and the characters who seek to know more about its mysteries drive the books and the TV series. Residents of the Silo are told to stay put and those who express curiosity about the outside world get to go there—to clean the Silo’s external sensors. No one who chooses to leave ever returns.

“This is the story of mankind clawing for survival, of mankind on the edge,” Howey wrote of Wool on his author site. “The world outside has grown unkind, the view of it limited, talk of it forbidden. But there are always those who hope, who dream. These are the dangerous people, the residents who infect others with their optimism. Their punishment is simple. They are given the very thing they profess to want: They are allowed outside.”

The first book focuses on Holston’s story, revealing that his wife died after leaving the Silo and following his journey as he seeks answers about what happened to her. Later installments focus on other characters that populate the dystopian world.

The Apple TV+ series appears to follow a similar path. Without giving too much away, the show will begin on Holston before switching gears to center on Juliette (Rebecca Ferguson), an engineer looking for answers about the silo while also trying to solve a murder.