Yes, it is official, friends: Silo seasons 3 and 4 are indeed happening at Apple TV+. Following the critically acclaimed debut of season 2, the streaming service announced that the hit sci-fi drama is officially renewed through season 4, with the fourth season slated to bring a thrilling end to Hugh Howey’s three-part, New York Times bestselling trilogy of dystopian novels.
Silo tells the post-apocalyptic story of the last 10,000 people on Earth. Their homes are silos built a mile deep underground to protect them from a toxic, deadly world outside. But here’s the thing: No one really knows if that’s the truth, the whole truth, and nothing but the truth, and they don't know when and why the silos were built. What they do know is that those who allow their curiosity to get the best of them and start digging for answers face fatal consequences.
While season 1 caught our attention and piqued our curiosity, season 2 captivated us entirely with its introduction of new characters, its breakdown of current characters, and its shocking revelations that have left us breathless and waiting for season 3.
Silo season 3 already began filming
Silo season 3 officially began filming in the UK in October 2024, but it's still a little early for an exact release date. With any luck, we'll be deeply involved in season 3 before the end of the year, and with even better luck, we'll be immersed in season 4 mid-2026... maybe. Hopefully.
In an interview with Collider, Ferguson said she believes they’ll be filming the last two seasons back-to-back, so there’s a hot chance we could see a shorter wait time between those two seasons (fingers crossed). Regardless of when seasons 3 and 4 debut, we’ll all be immersed in watching this epic sci-fi thriller wrap itself up.
What might happen in season 3 (and 4)
WARNING: MINOR SPOILERS AHEAD for the Silo book trilogy
Howey’s Silo book series contains three books: Wool, Shift, and Dust (in that order). Seasons 1 and 2 cover the plot of Wool, and seasons 3 and 4 allegedly will adapt books 2 and 3, Shift and Dust.
In Shift, we are brought back in time to see and focus on how the silos were originally built. In essence, it’s a prequel to Wool, and I suspect Silo season 3 will serve as a prequel to seasons 1 and 2. Shift also focuses on completely different characters, with Juliette appearing only at the very end. So, what does this mean for Ferguson’s character? Will she return for season 3?
According to Yost, yes, she will:
“In the book Shift, Juliette doesn’t appear until the last page … It’s about this silo [No. 18], but it’s also the origin story of the whole silo project. I would say that we have Rebecca Ferguson playing Juliette, and she is not just going to be in the last scene of the season.”
Yost’s comment makes me think he’s about to play with the chronology of Howey’s novels and disperse Juliette’s story throughout the origin story of the silos. And that would make sense, because many parts of Shift directly impact events in Wool and give readers much more information about the wider world, equipping them with more context about everything that has happened in Silo 18 since it was built.
To properly portray these direct correlations, it might mean that we'll see two different timelines play out in season 3. Yost is no stranger to altering timelines, as we saw in season 2 when he introduced Steve Zahn’s character, Solo/Jimmy, who doesn’t appear until later in the novels. Now, Juliette does have a bigger role in Dust, which could serve as the basis for the fourth and final season of the sci-fi thriller. That posit does have its drawbacks, though, because of how crucial Ferguson’s appeal has been to the show’s initial popularity. At this point, we'll just have to wait and see.
A summary of seasons 1 and 2
When mechanical engineer Juliette Nichols (Rebecca Ferguson) goes searching for answers about the death of her lover, she wanders right into a mystery that delves much deeper and is far more tangled than she could have ever imagined. As it turns out, this mystery leads her to discovery that in this world, if the lies don’t kill you first, the truth definitely will.
Season 1 saw Juliette face near-fatal consequences after she followed her curiosity, dug into Silo 18 secrets, and stood up to a shady system. She was then subsequently forced to venture out into the dangerous, toxic world of unknowns. When she surpassed the point where others previously sent outside died, leaders in her silo wasted no time in lying to the residents, telling them Juliette did not survive her mission; she just managed to walk a little farther before dying.
As we saw in season 2, she did not die but instead made it to another silo, Silo 17, which she didn’t even know existed (and while we might've suspected it, neither did we... unless you read the books). There she found new people, each a survivor of something horrific that left them chocked full of ambition, desperation, and some extreme psychological trauma. Juliette also learned a shocking bit of silo history that led her to spend her time there figuring out how to safely return to the very place that cast her out.
As skeptics emerged back in Silo 18, they openly doubted the information being given to them, and rebellion set in as hell broke loose, courtesy of the efforts of one villainous man, Bernard Holland (Tim Robbins). Shocking truths emerged, horrible lies were exposed, and tense cliffhangers abounded in season 2, which has earned praise as being “genuinely brilliant,” “immensely satisfying,” and “one of the best sci-fi TV shows today.”
In addition to Ferguson and Robbins, season 2 stars Common, Harriet Walter, Chinaza Uche, Avi Nash, Alexandria Riley, Shane McRae, Remmie Milner, Billy Postlethwaite, Rick Gomez, Clare Perkins, Caitlin Zoz, Tanya Moodie, and Iain Glen. It also stars series newcomer Steve Zahn, who gives the performance of a lifetime in his prismatic depiction of an isolated, terrorized, traumatized boy trapped in a grown man’s body. Thanks to Juliette, he is able to reconnect to his own truth and experience human connection again; thanks to him, she is able to return home to her silo and stop the rebellion before anyone dies.
Silo season 2's finale left us smack dab in the middle of one of the show's most intense cliffhangers. Juliette entered Silo 18, only to be confronted by a now-nihilistic, gun-wielding Bernard; then, in a shocking move, what seemed to be the silo's intelligence itself trapped them in a corridor and set it on fire.
Are Juliette and Bernard still alive? Did they survive? What really happened? And what was with that post-scene that took us back to a lively, bustling Washington D.C. and again left us with another cliffhanger? Where might we be headed in seasons 3 and 4?
Silo seasons 1 and 2 are currently streaming on Apple TV+.