Juliette Nichols survived three minutes inside a fire chamber that should have killed her. She walked back into Silo 18 alive. And now she can’t remember any of it.
That’s where Silo picks up in its third season, which premiered on Apple TV on July 3. Rebecca Ferguson’s engineer-turned-sheriff-turned-mayor returns with amnesia, stripped of the one thing that made her dangerous: knowledge. She discovered what’s outside, she learned the truth about the silos, and none of it stuck. The Overseer controls what she remembers now. It’s the cruelest possible reset for a character who spent two seasons clawing toward the truth.
Critics are responding accordingly. Season 3 opened with a 100% Rotten Tomatoes score based on nine reviews, with individual ratings ranging from 7/10 to 10/10. That’s an upward curve from season one’s 88% and season two’s 92%. For a show entering its penultimate chapter, that’s the trajectory you want.
The final season is already in the can
Here’s the detail that matters most for anyone investing in the next 10 weeks of episodes: the fourth and final season has already finished filming.
Ferguson and creator Graham Yost spoke to Collider ahead of the season 3 premiere, and what they said should reassure anyone who’s been burned by mystery shows that lose the plot. Yost confirmed that the series will answer nearly every lingering question by the time it wraps.
“There are mysteries in every season and almost all of them are answered by the end of Season 4,” Yost said. “We wanted to make sure we answered enough by the end of Season 3 so the audience wouldn’t feel like we were dragging it out unfairly.”
Ferguson kept it simpler. “Season 4 is about the answers that come from Season 3 and how everything will develop,” she said.
Yost also offered a comparison that’ll land with a specific audience: he described the fourth season as the final level of a video game, where the heroes face the ultimate boss after clearing every obstacle before it.
Going back to before the world ended
Season 3 doesn’t just push forward. It splits its timeline between the present (Juliette navigating Silo 18 with no memory and a new title) and the “Before Times,” centuries earlier, when the silos were built and the surface was still habitable.
Jessica Henwick joins the cast as Helen Drew, a journalist investigating a story that pulls her toward something she can’t undo. Ashley Zukerman plays Congressman Daniel Keene, who gets drawn into the same conspiracy. Their plotline was teased in the final scene of season two’s finale, set in a Washington, D.C., restaurant after a dirty bomb detonation, and now it’s a full second narrative track running alongside Juliette’s story.
Colin Hanks also appears as a billionaire industrialist character whose chilling line from the trailer sets the tone for the prequel thread: “The end of the world cannot be stopped. It can only be survived.”
The first two seasons adapted Hugh Howey’s novel Wool. Seasons 3 and 4 pull from the remaining books in the trilogy, Shift (a prequel about the silo’s origins) and Dust (the conclusion). Because Shift focuses on characters who predate everyone we’ve spent two seasons caring about, Yost and his writers are weaving the prequel material into the present-day narrative rather than isolating it. Smart call. You get the origin story without losing the cast you’re attached to.
Who’s back and what’s changed inside Silo 18
Ferguson returns alongside the ensemble: Common as Robert Sims, Harriet Walter as Martha Walker, Chinaza Uche as Paul Billings, Shane McRae as Knox, Remmie Milner as Shirley, Avi Nash as Lukas Kyle, Steve Zahn as Solo/Jimmy, Clare Perkins as Carla McLain, Rick Gomez as Patrick Kennedy and Alexandria Riley as Camille Sims, who has taken over as head of IT following Bernard’s death. Tim Robbins’ Bernard didn’t survive the fire chamber.
That last point reshapes the power dynamics inside Silo 18. Camille is now the person in charge, and Juliette’s new title as mayor puts two women at the top of a structure built to keep its residents controlled and uninformed. How long that arrangement holds is one of the season’s central tensions.
Apple renewed Silo for both its third and fourth seasons in December 2024 after strong viewership and critical reception. Yost noted at the time that the four-season plan was always the goal. “It has been a richly rewarding experience to adapt Hugh’s epic novels with our partners at Apple, and we are thrilled to have the opportunity to bring this complete story to the screen over the course of four seasons,” he said.
10 episodes, every Friday, through September
New episodes drop weekly on Fridays at 12:00 a.m. ET on Apple TV, running through the season finale on Sept. 4. Apple TV costs $12.99/month or $129/year, with a seven-day free trial for new subscribers. The first two seasons are available to stream in full.
Chris Evangelista of SlashFilm put it well in his 7/10 review: there has “never been a better time to get on board with this show.” He’s right. Silo doesn’t generate the conversation that Severance does, and it lacks the cultural footprint of some of Apple TV’s flashier originals. But it’s a show that knows exactly how many episodes it has left and has already filmed the ending. In the age of premature cancellations and indefinite renewals, that’s worth more than hype.
