# Silo (TV series)

Silo is an American science fiction dystopian drama television series created by Graham Yost, based on the Silo trilogy of novels (Wool, Shift, and Dust) by author Hugh Howey. Set in a dystopian future where a community exists in a giant underground silo comprising 144 levels, it stars Rebecca Ferguson as an engineer who becomes embroiled in the mysteries of its past and present. Rashida Jones, David Oyelowo, Common, Tim Robbins, Harriet Walter, Avi Nash, Rick Gomez, Chinaza Uche, Shane McRae, Remmie Milner, Alexandria Riley, Clare Perkins, Billy Postlethwaite, and Steve Zahn also star.
Development of a film adaptation of Wool began in 2012. By the end of the decade, the project was shelved, and was picked up as a series by Apple TV+ in May 2021. Principal photography began in August 2021 and the ten-episode first season began streaming on May 5, 2023. The second season premiered on November 15, 2024. Both seasons received positive reviews from critics, particularly for the world-building, production design and Ferguson's performance. In December 2024, the series was renewed for both a third season and a concluding fourth season.

## Premise

In a dystopian future where communities exist in silos that extend 144 stories underground, roughly 10,000 people in each silo live in a society bound by regulations they believe are meant to protect them.

## Cast and characters
### Main

* Rebecca Ferguson as Juliette Nichols, an engineer who works on the generators in the lowest levels of the Silo where she was born.
** Amelie Child-Villiers portrays a young Juliette
* Rashida Jones as Allison Becker (season 1), a woman who works in the IT Department in her Silo and is married to Holston. During their attempts to conceive a child, she becomes suspicious of her Silo's true history and how it is governed
* David Oyelowo as Holston Becker (season 1), the devoted husband of Allison and the sheriff of their Silo
* Common as Robert Sims, the head of security for Judicial, who maintains order within his Silo
* Tim Robbins as Bernard Holland, the strict head of the IT Department in his Silo
* Harriet Walter as Martha Walker, an electrical engineer who runs a workshop in the lower levels of the Silo and acts as a parental figure to Juliette
* Avi Nash as Lukas Kyle, a systems analyst in the IT Department who is curious about the world outside their Silo
* Rick Gomez as Patrick Kennedy, a maintenance worker and former smuggler of "relics", objects from the world before the Silo
* Chinaza Uche as Paul Billings, the newly assigned chief deputy and a former Judicial administrator who is afflicted with the "Syndrome", a medical condition that causes tremors
* Shane McRae as Knox (season 2; recurring season 1), the head of the Mechanical level in the Silo and Juliette's boss
** Charlie Coombes portrays a young Knox
* Remmie Milner as Shirley Campbell (season 2; recurring season 1), an engineer in Mechanical who is Juliette's closest friend and colleague
** Ida Brooke portrays a young Shirley
* Alexandria Riley as Camille Sims (season 2; guest season 1), Robert's wife, the mother of their son, and a former raider
* Clare Perkins as Carla McLain (season 2; guest season 1), Walker's ex-wife and the head of the supply department
* Billy Postlethwaite as Hank (season 2; recurring season 1), a deputy who works in the lower levels
* Steve Zahn as Jimmy Conroy / "Solo" (season 2), the only living survivor of the rebellion in Silo 17
** Cameron Bell portrays a young Jimmy
* Ashley Zukerman as Daniel (season 3; guest season 2), a United States congressman during the time before the Silos were created
* Jessica Henwick as Helen (season 3; guest season 2), an inquisitive journalist based in Washington, D.C.

### Recurring

* Will Patton as Samuel "Sam" Marnes (season 1), a deputy who works under Sheriff Holston and closely with Mayor Jahns
* Ferdinand Kingsley as George Wilkins (season 1), a computer geek who runs a repair shop. He seeks out Allison for her help to uncover the secrets of the Silo
* Chipo Chung as Sandy, a clerical worker in the sheriff's department
* Matt Gomez Hidaka as Terry Cooper (season 1; guest season 2), a rookie engineer in the lower levels and Juliette's shadow
* Olatunji Ayofe as Teddy, a worker in Mechanical and one of Juliette's colleagues
* Iain Glen as Dr. Pete Nichols (seasons 1–2), an obstetrician and the father of Juliette, from whom he has been estranged since she was a teenager
* Angela Yeoh as Molly Karins, a deputy who works in the mid-levels
* Tanya Moodie as Judge Mary Meadows (seasons 1–2), the head of Judicial who enforces the Pact, a list of rules that all Silo residents must follow
* Caitlin Zoz as Kathleen Billings, Paul's wife and the mother of their daughter
* Akie Kotabe as Diego, a Watcher monitoring the Silo
* Christian Ochoa as Rick Amundsen (season 2; guest season 1), a high-ranking raider, a group of armed enforcers working for Sims

### Guest

* Geraldine James as Ruth Jahns (season 1), the elected mayor of the Silo
* Sophie Thompson as Gloria Hildebrandt (season 1), a paranoid woman who became the Silo's fertility counselor after failing to conceive a child herself
* Sienna Guillory as Hanna Nichols (season 1), a surgeon and the deceased mother of Juliette
* Henry Garrett as Douglas Trumbull (season 1), an enforcer for Judicial who is loyal to Sims
* Sonita Henry as Regina Jackson (season 1), a former relic dealer and lover of George
* Will Merrick as Danny (season 1), a criminal hacker who disrupts the IT Department's security network
* Ross McCall as the Silo 17 Sheriff (season 2), the leader of the rebellion in Silo 17
* Nick Haverson as Russell Conroy (season 2), the head of the IT Department in Silo 17 and Solo's father
* Imogen Butler-Cole as Gwen Conroy (season 2), Solo's mother
* Pippa Winslow as Gladys (season 2), a worker in Mechanical during Juliette's childhood
* George Robinson as Mark Chambers (season 2), the overseer of a manufacturing workshop
* Sacharissa Claxton as Frances Boyer (season 2), Patrick's niece
* Georgina Sadler as Audrey (season 2), the leader of a group of young orphaned survivors in Silo 17
* Orlando Norman as Rick (season 2), Audrey's boyfriend and the father of their two children
* Sara Hazemi as Hope / "Eater" (season 2), the outcast of Audrey's group
* Stuart Milligan as Terrance Penbrook (season 2), a descendant of Salvador Quinn, the former head of IT over 140 years prior
* Lolita Chakrabarti as Lukas' mother (season 2)
* ↑ Jones appears in only one episode although credited with the main cast.
* ↑ Oyelowo is credited with the main cast in episodes 1 and 2, and is credited as a 'special guest star' in all subsequent appearances.
* ↑ Zahn remained uncredited until the episode "The Harmonium".

## Episodes

| Season | Episodes | Episodes | Originally released | Originally released |
| Season | Episodes | Episodes | First released | Last released |
| 1 | 10 | 10 | May 5, 2023 (2023-5-5) | June 30, 2023 (2023-6-30) |
| 2 | 10 | 10 | November 15, 2024 (2024-11-15) | January 17, 2025 (2025-1-17) |

### Season 1 (2023)

| No. overall | No. in season | Title | Directed by | Written by | Original release date |
| 1 | 1 | "Freedom Day" | Morten Tyldum | Graham Yost | May 5, 2023 (2023-5-5) |
| In a massive underground bunker called the "Silo", a community thrives without knowing their history, as records were supposedly destroyed 140 years earlier during a failed uprising. Sheriff Holston Becker tells Deputy Sam Marnes that he wants to "go out". Three years earlier, Holston and his wife Allison receive permission for her doctor to remove her birth control implant for 365 days. During this time Allison learns subversive beliefs about the Silo from fertility expert Gloria Hildebrandt, and helps IT expert George Wilkins explore a forbidden hard drive from before the rebellion. Allison tells a skeptical Holston that those in power are lying to them, and that the view on Silo's screens of a dead outside world is fake; as evidence she offers the birth control implant, which she just removed from her thigh with a knife. As Allison bleeds out, Holston runs through the halls of the silo to find the doctor but stops when Deputy Marnes tells him that Allison is in the cafeteria. Allison reveals her findings to the cafeteria and ultimately declares that she wants to "go out". This results in inevitable fulfillment of that desire as written in ‘The Pact’. Allison promises to clean the Silo's external camera if the outside is beautiful. She is dressed in an environmental suit and exits on her one-way journey. Silo residents watch her clean the camera and then collapse, seemingly dead. Two years later, Holston investigates George's death and meets Juliette Nichols, an engineer who claims he was murdered. ||||||
| 2 | 2 | "Holston's Pick" | Morten Tyldum | Jessica Blaire & Cassie Pappas | May 5, 2023 (2023-5-5) |
| Holston learns from Juliette that George, her lover, collected forbidden historical relics. Upon learning that George and Allison worked together, Holston agrees to investigate and promises to send Juliette a signal when he finds something. A few months later, Holston leaves the Silo and is shocked to see that the outside is lush and beautiful like Allison claimed. He cleans the camera, takes off his helmet, and on camera appears to crawl to Allison's body before dying. Mayor Ruth Jahns learns that Holston left behind a statement nominating Juliette to be his replacement as sheriff. Juliette knows that George was looking for a door and tries to retrace his steps in the watery dig space underneath the Silo. ||||||
| 3 | 3 | "Machines" | Morten Tyldum | Ingrid Escajeda | May 12, 2023 (2023-5-12) |
| Mayor Jahns and Deputy Sam descend 144 levels to meet Juliette. Along the way, Jahns meets Juliette's estranged father, Dr. Pete Nichols and Juliette's engineer friend, Martha Walker, for opinions about Juliette's character. Despite the disapproval of Judge Meadows, head of Judicial, and Bernard Holland, head of IT, Jahns offers Juliette the role of sheriff. Juliette declines but changes her mind when she's given Holston's badge, which has the word "TRUTH" carved on the back. Juliette requests that Jahns allow the main generator to be switched off for repairs, which has never been done. At shutdown, the Silo's screens briefly show a healthy green view of the outside, though no one seems to notice this. With difficulty, the Mechanical team fixes the main generator. Before leaving for her new job, Juliette asks Walker to study a camcorder she found among George's relics. Marnes and Jahns confess their love for each other, before Jahns collapses with blood in her mouth. ||||||
| 4 | 4 | "Truth" | David Semel | Remi Aubuchon | May 19, 2023 (2023-5-19) |
| Ruth Jahns is dead; Marnes believes she was poisoned, and that he was the real target because they drank from each other's water flasks. Bernard, as Mayor Pro Tem, swears Juliette in as the new sheriff. Juliette asks Marnes to help her investigate George's death, in return for her helping him investigate Jahns's death. Robert Sims, of Judicial, tells Marnes that Judge Meadows is ready to remove Juliette as sheriff but Marnes tells him to let Juliette quit on her own. Later, Marnes is attacked in his apartment. Juliette meets Lukas, a resident who spends late nights in the cafeteria. Juliette finds Holston's file on George but cannot find George's hard drive that Holston confiscated. In a flashback, Juliette leaves home at thirteen after the deaths of her mother, Hanna and younger brother, Jacob. ||||||
| 5 | 5 | "The Janitor's Boy" | David Semel | Graham Yost | May 26, 2023 (2023-5-26) |
| Sam Marnes is found dead. Paul Billings, Judicial's original choice for sheriff, is made Juliette's chief deputy. Sandy, who works in the sheriff's office, tells Juliette to find Marnes's killer before Judicial picks a scapegoat. Juliette discovers that Doug Trumbull, who works for Judicial, planted evidence to frame resident Patrick Kennedy for Marnes's murder. Sims tells Doug that his father was supposedly a janitor but actually had a secret job that was crucial to the Silo's survival. Sims kills Doug before he can be arrested, and Doug is posthumously blamed for Marnes and Jahns's murders. Juliette learns that Lukas has been studying the cafeteria's display screens at night to observe the movement of the "lights" in the sky, Silo residents being ignorant that these are stars. Walker shows Juliette that the camcorder's technology is more advanced than what is permitted in the Silo. Juliette retrieves one of George's relics in the hopes of reopening the investigation into his death. ||||||
| 6 | 6 | "The Relic" | Bert & Bertie | Aric Avelino | June 2, 2023 (2023-6-2) |
| Juliette arranges for the relic to be found in Doug's apartment and uses it as an excuse to track down supposed relic dealer Regina Jackson, who turns out to be George's previous lover who bought relics for him. Sims learns about George's connection to the relic and formally confronts Juliette; Bernard accepts Juliette's claim that she didn't plant the relic but he orders her to stop investigating Doug's motives for murdering Jahns and Marnes. Juliette and Billings argue over her difficulty in trusting him and she reveals that she knows he has the ‘Syndrome’, a medical condition that should disqualify him from being a deputy. Regina tells Juliette that she didn't report George's hard drive to Judicial but she did tell "the man who knows everything" about it, after he threatened her loved ones. Regina gives Juliette a cherished relic she received from George: an old children's travel book. While Juliette browses the book, she is watched in her apartment by a surveillance team that has cameras all over the Silo, with equipment much more advanced than the rest of the Silo. ||||||
| 7 | 7 | "The Flamekeepers" | Bert & Bertie | Jessica Blaire | June 9, 2023 (2023-6-9) |
| Sims is part of the surveillance team and monitors Juliette's movements using the cameras. Juliette seeks out Gloria, who is being drugged on Meadows's order. Despite Juliette's offer to resign as sheriff, Meadows says she can't lift the order. Billings confronts Juliette when she neglects her duties; she tells him about her investigation into George's murder and he decides to cover for her. Lukas tries to kiss Juliette but she rebuffs him. Bernard tells Juliette that he fears Meadows will move against them and encourages her to find a way to control Meadows. With her father's help, Juliette is able to question Gloria and learns that she is part of the Flamekeepers, a secret group dedicated to remembering the past, whose members are being systematically killed. Juliette's mother befriended Flamekeepers but Juliette's father obeyed orders to prevent them from having children. Juliette realizes that surveillance cameras are behind the wall mirrors and retrieves George's hard drive from where Holston hid it in Gloria's room. Sims's raiders arrive at Gloria's room to apprehend Juliette, who isn't there. ||||||
| 8 | 8 | "Hanna" | Adam Bernstein | Jeffery Wang & Ingrid Escajeda | June 16, 2023 (2023-6-16) |
| Judicial searches the sheriff's office for the hard drive, but cannot find it. Juliette retaliates by using Billings's knowledge of the Pact to temporarily arrest Sims. While Sims is in custody, Juliette searches his office and finds files on Hanna, Walker, and Shirley Campbell. Hanna's file confirms that Judicial's surveillance cameras are how they knew that Hanna had built an illegal multi-lens magnifier; Hanna and Juliette had believed that Pete told Judicial. Juliette reconciles with Pete, and he tells her that Hanna's subversive behavior and suicide were a response to Jacob's death, which Hanna believed the magnifier technology could have prevented. Juliette is unable to access the hard drive's content; Lukas is too afraid to help and Judicial's checkpoints prevent her from reaching Walker. Bernard finds Juliette and reveals himself to be the true person in charge of the Silo and responsible for Jahns's and Marnes's deaths. Bernard and Sims arrest Juliette, take the hard drive and fraudulently claim that Juliette has asked to "go outside". Juliette jumps off the Silo's central stairs to escape with the hard drive. ||||||
| 9 | 9 | "The Getaway" | Adam Bernstein | Lekethia Dalcoe | June 23, 2023 (2023-6-23) |
| Juliette escapes and evades Judicial's cameras. Billings investigates Juliette's apartment and finds the children's travel book; he keeps one page but burns the rest. Juliette breaks into Sims's apartment and uses his computer to access the hard drive, on which she finds a video message George made for her. Bernard arrests Lukas and learns the hard drive's serial number, which he uses to find Juliette's location. Sims and his raiders rush to the apartment but Sims's wife allows her to escape. Juliette gets Patrick's help with Danny, an IT contact, to access the hard drive. She watches the rest of George's video, in which he tells her that he loves her and that she needs to find the door underneath the Silo. Following George's advice, Juliette, Patrick and Danny watch a video from a past cleaning, which shows a lush green landscape with birds flying outside the Silo. ||||||
| 10 | 10 | "Outside" | Adam Bernstein | Fred Golan | June 30, 2023 (2023-6-30) |
| Juliette has Danny broadcast the outside footage to the Silo but this is quickly shut down by Bernard. Billings is questioned by Sims about his condition, and later tells his wife that they are making an exception so he can be sheriff. Juliette escapes to Mechanical, where she talks to Walker before being arrested. Bernard offers Juliette a deal: if she will go out willingly, he will tell her what happened to George and ensure that Mechanical will not be punished. Bernard shows Juliette footage of George jumping off the stairs to avoid interrogation. Bernard destroys the hard drive but later recovers the disc, after Juliette mentions a door underneath the Silo. Bernard sentences Lukas to the mines. Juliette goes outside and her helmet display shows the same video footage of a lush landscape from the previous cleaning. She realizes the deception, discovering that the reality is the desolate view on the Silo's screens. Because Walker has arranged for the heat tape on Juliette's suit to be of sound quality, instead of dying, Juliette climbs out of the crater that surrounds the Silo and goes out of view of its residents. She sees dozens of similar craters, each with a silo, and a ruined city on the horizon. ||||||

### Season 2 (2024–25)

| No. overall | No. in season | Title | Directed by | Written by | Original release date |
| 11 | 1 | "The Engineer" | Michael Dinner | Graham Yost | November 15, 2024 (2024-11-15) |
| In a flashback, Silo 17 revolts, and its population escapes. In the present, Juliette breaks into Silo 17 by climbing over the corpses of its dead inhabitants littered outside the entrance. Juliette explores the silo’s upper levels to find it abandoned, and the lower levels flooded. The bridge leading into the IT department has been destroyed, so Juliette builds a makeshift bridge that collapses after she gets across. In a flashback, young Juliette starts her new life in Mechanical, where she helps sort through trash from the upper levels and befriends Shirley. After struggling with her new position, she impresses the other workers by fixing a broken toy and begins working under Walker. In the present, Juliette continues exploring and follows the sound of music to the locked vault door in the IT department. After Juliette fails to open the door, a man on the other side warns her that if she tries again, he will kill her. ||||||
| 12 | 2 | "Order" | Michael Dinner | Fred Golan | November 22, 2024 (2024-11-22) |
| Bernard watches Juliette's suit camera from inside the vault and sees her approach Silo 17 before it cuts off. As Juliette refused to clean, Bernard understands that her sign of defiance may lead to revolution. He places the deputies under Sims's command and sets a mandatory curfew to control the silo’s population, who are asking questions about Juliette's survival. Bernard tries to convince Meadows to help, and has Walker and her ex-wife Carla locked up for smuggling Juliette the tape that sealed her suit. Shirley starts interrogating people on the lower levels to demand answers, while Knox tries to stop her. Bernard gives his speech to the silo and claims that IT produced a new tape that allowed Juliette to survive longer, but remains adamant that she is dead. Meadows endorses him. While the majority of the population seems pleased with the explanation, Shirley remains unconvinced and organizes a secret meeting outside curfew. After Bernard thanks Meadows for her help, she demands to be given an environmental suit with good tape in order to go outside. ||||||
| 13 | 3 | "Solo" | Aric Avelino | Cassie Pappas | November 27, 2024 (2024-11-27) |
| In Silo 17, Juliette learns from the man in the vault, "Solo", that 50 silos exist and that her actions may cause a revolution. Solo gives Juliette food and suggests that she can use a firefighter's suit to return to her silo, but the fire safety equipment is in a flooded area. Juliette requests Solo's help to reach it; he at first refuses but changes his mind and exits the vault. In Silo 18, the worker Teddy is arrested for writing the graffiti "Juliette Lives". Sims offers an incarcerated Patrick a drug that will help him forget his deceased wife in exchange for a favor and recruits retired raiders to send down to Mechanical. Shirley leads some protestors to demand Teddy's release, but Patrick throws a firebomb at the deputies, and in the resulting chaos the new engineer Cooper is killed. Pete meets a woman who hopes to win a lottery that will allow her to have a child, and defies orders not to remove her birth control by performing the procedure anyway. Billings interviews everyone present during Juliette's arrest and brings his report to Meadows, stating that Juliette never asked to go outside. ||||||
| 14 | 4 | "The Harmonium" | Aric Avelino | Sal Calleros | December 6, 2024 (2024-12-6) |
| With Solo's help, Juliette builds an air pump to help her through the flooded levels to collect a firefighter suit. Solo tells Juliette about the outside world from before and struggles with anxiety about leaving the vault. Knox shares with Shirley his belief that their silo has had multiple rebellions, which were blamed on Mechanical because of their ability to shut down the silo. He also requests to speak with Meadows, who agrees to meet. Sims becomes suspicious of Bernard's relationship with Meadows and fabricates a movement to demand Meadows's impeachment. Meadows allows Lukas to protest his sentence and reduces it to five years. Billings investigates the riot in Mechanical and learns that the body of the instigator has disappeared, and Judicial has claimed Cooper's body. Bernard poisons Meadows, and before she dies she tells him that on the hard drive Juliette stole, there's a coded letter from Salvador Quinn, who was head of IT during the rebellion 140 years ago. Knox, Shirley, Walker, and Carla arrive at Judicial, where Bernard has set up Meadows's body to frame Knox and Shirley for her murder. Sims whips up a crowd and sends it after them. ||||||
| 15 | 5 | "Descent" | Amber Templemore | Jenny DeArmitt-Stran | December 13, 2024 (2024-12-13) |
| Solo asks Juliette to repair a water pump because the water level is rising and will reach IT in ten months, but Juliette insists she needs to return to her silo immediately. Juliette suspects that Solo is lying about his identity, and he reacts angrily to her questioning. Juliette finds a usable suit helmet but collapses from injuries. In Silo 18, Bernard is aware that Sims fabricated the movement against Meadows and denies him the role of Bernard's shadow but makes him Judge to replace Meadows, which frustrates Sims. Sims's wife Camille helps Knox and Shirley evade the mob. Rick Amundsen, the new head of Judicial Security, has Carla arrested but Knox, Shirley, and Walker bypass the blockade and travel to the lower levels. Bernard has Lukas fix Juliette's hard drive, revealing hidden connections in the silo to the outside world and a coded letter by Salvador Quinn to his wife. Billings and deputy Hank track down Patrick, who offers to tell Billings truths about the silo. ||||||
| 16 | 6 | "Barricades" | Michael Dinner | Jeffery Wang | December 20, 2024 (2024-12-20) |
| Tensions rise with Bernard blocking supplies to the lower levels and Knox having weapons made. At Billings's request, Pete travels to the lower levels to treat Patrick. Patrick tells Billings how he'd helped Juliette with the hard drive and accepted a deal from Sims to be agent provocateur at the protest in Mechanical. Bernard questions Camille about her action to protect Knox and Shirley, but she deflects him. Knox and Shirley lead a group attack on the blockade and push it ten floors higher, claiming the critical farm on level 122. Billings questions Walker, Knox, and Shirley about Meadows's death. When Billings tells Bernard via radio that he wants to open a formal investigation into Meadows's death, Bernard shuts down radio communication. Lukas works on decoding Quinn's letter, and the sophistication of the cipher prompts Bernard to make Lukas his shadow so he can access the Legacy. In Silo 17, Juliette wakes after being treated by Solo, who has hidden her suit to force her to fix the pump before leaving. ||||||
| 17 | 7 | "The Dive" | Michael Dinner | Katherine DiSavino | December 27, 2024 (2024-12-27) |
| Bernard introduces Lukas to the Legacy, an advanced computer behind a vault that contains all their secret knowledge and records, though the origins of the silo beyond 352 years earlier remained lost. Using the Legacy to help with his research, Lukas suspects the letter uses a book cipher. Mechanical sends paper messages to the upper levels encouraging citizens to ask what IT has been hiding from them before shutting down power in the silo, revealing that IT has their own independent power source. Bernard clashes with Sims, who is still angry about being set aside. Sims confronts Camille about her actions; she explains that she wants to play both sides for their safety, and promises to not hide anything from him again. Billings and Hank follow up on spies who are trying to sow discord in Mechanical. Walker worries about Carla and briefly switches on one of IT's cameras to send a message up top, which Bernard receives. In Silo 17, Juliette performs a deep dive to repair the water pump for Solo and almost drowns when her air supply is cut. After surfacing, Juliette finds evidence of a struggle and suspects there's someone else in the silo. ||||||
| 18 | 8 | "The Book of Quinn" | Amber Templemore | Remi Aubuchon | January 3, 2025 (2025-1-3) |
| Juliette gets the bends and has to dive again to recover. After surfacing, she is confronted by a figure who shoots her with an arrow and threatens to kill her. Juliette searches for her attacker and finds three young people. In Silo 18, Lukas tracks down Quinn's descendants and learns that they gave Quinn's copy of the Pact to Meadows years earlier. Bernard tells Lukas that Quinn destroyed the records 140 years ago and drugged the water in order to make citizens forget their history, to stop the rebellions that had been occurring every 20 years. Using Quinn's Pact, Lukas starts decoding Quinn's letter. Sims, with Camille's help, learns that Lukas is investigating for Bernard. Walker meets Bernard and agrees to be his informant in order to save Carla. Consequently a group of Mechanical who break into Supply are arrested by raiders. Billings's wife Kathleen learns that Billings saved a page of a picturebook from the 'before times', and demands to see it. ||||||
| 19 | 9 | "The Safeguard" | Amber Templemore | Jessica Blaire | January 10, 2025 (2025-1-10) |
| Juliette is confronted by Audrey, leader of five young survivors, who orders Juliette to open the vault, so they can access the food. Audrey has captured Solo and wants to kill him for the death of their parents. Juliette realizes that Solo was a child at the time of the rebellion, and Solo confesses that he killed the group's parents out of self-defense when they broke into the vault. Solo and the group make peace, and he allows everyone into the vault. In Silo 18, Lukas learns that there are 50 other Silos and, following Quinn's letter, travels to the lower levels. Lukas finds the tunnel underneath, where at a door a computer voice warns him not to tell anyone what he has seen, or they will initiate "the safeguard". Billings gives Sims the picturebook page, which makes Camille and Sims consider joining the rebellion. Patrick tells Kathleen his suspicion that the silo’s display of the outside is a lie. Bernard blames the rebels' actions on Billings, but not all the top level deputies believe him. Bernard spies on Knox and Walker discussing the rebellion's plans. ||||||
| 20 | 10 | "Into the Fire" | Amber Templemore | Aric Avelino | January 17, 2025 (2025-1-17) |
| Walker works with Knox and the other rebels to use Bernard's camera to send him misinformation. They trick Bernard into sending the raiders below and transferring all rebels up top, after which Pete sacrifices himself to blow up the stairs in between. The up top deputies side with the rebels after receiving Billings's message via Sims. Patrick agitates the citizens into a mob that demands answers from Bernard. Lukas tells Bernard what he learned and resigns, which causes a despondent Bernard to make Sims his new IT shadow, handing over the vault key and password. Sims and his family enter the vault, but the Legacy says only Camille can stay. In Silo 17, Solo tells Juliette about the safeguard procedure, a pipe that can pump enough poison to kill everyone, and how it can be stopped. Juliette uses the firefighter suit and returns to Silo 18, which is seen inside and celebrated, but she shows a message warning them not to leave. Juliette enters as Bernard is leaving, and they are locked in the incinerator as it fires up. In an apparent flashback in Washington, D.C., a woman named Helen questions a new congressman about the possibility of the US retaliating against Iran for supposedly having detonated a dirty bomb on US soil. ||||||

## Production
### Development

The project's development was announced as a feature film at 20th Century Fox, which entered negotiations to acquire the self-published e-book Wool by Hugh Howey on May 11, 2012. Five days later, 20th Century Fox acquired the rights, with Ridley Scott and Steven Zaillian among those attached to produce. On November 28, it was announced that J Blakeson was in negotiations to write and direct. It was then announced on June 5, 2015, that Nicole Perlman would rewrite the screenplay, with Blakeson no longer involved in the project. The film was ultimately shelved as a result of the acquisition of 21st Century Fox by Disney.
By July 30, 2018, a new iteration of the project was in development for television at AMC, with LaToya Morgan attached to write under her overall deal at AMC Studios. The series eventually moved to Apple TV+ on May 20, 2021, receiving an order for ten episodes. Graham Yost replaced Morgan as creator and writer, marking his third series at Apple TV+ under his overall deal with the network. Morten Tyldum was also attached to direct and executive produce, with Yost as showrunner. The show was renewed for a second season in June 2023. In April 2024, Rebecca Ferguson stated in an interview that they are looking to shoot seasons 3 and 4 back-to-back, which would end the series. On December 16, 2024, the series was renewed for a third and a fourth season, with it set to conclude with the latter.

### Writing

Alongside Yost, Jessica Blaire, Cassie Pappas, Ingrid Escajeda, Remi Aubuchon, Aric Avelino, Jeffery Wang, Lekethia Dalcoe, and Fred Golan served as writers.

### Casting

With the series order announcement, it was also announced that Rebecca Ferguson had been cast in a lead role. Tim Robbins joined the cast in August 2021, and Rashida Jones, David Oyelowo, Common, Harriet Walter, Avi Nash and Chinaza Uche joined in the following months. On July 27, 2024, it was announced at San Diego Comic-Con that Steve Zahn had joined the cast for the second season. On January 17, 2025, it was announced that Ashley Zukerman and Jessica Henwick had joined the cast as series regulars for the third season.

### Filming

Principal photography began in late August 2021 in Hoddesdon, Hertfordshire, and was scheduled to last until the second quarter of 2022. Mark Patten, David Luther, and Laurie Rose were cinematographers. Gavin Bocquet was the production designer, credited with the design of the silo. The main set consists of three levels of stairs decorated to represent particular locations.
The second season began filming in late June 2023 at Hoddesdon Studios, using the same set as season one. Filming was officially suspended in July due to the 2023 SAG-AFTRA strike. Filming restarted in early December 2023, and wrapped on March 8, 2024. Filming of season three began in October 2024, also at Hoddesdon Studios, as well as at OMA One and OMA X Film Studios in Enfield, London.

### Music

In March 2023, Atli Örvarsson was announced as the series's composer. He collaborated with Tyldum on the Apple TV+ series Defending Jacob.

## Release

Silo had its special screening during the 2023 Canneseries on April 14, 2023. The television series premiered on Apple TV+ on May 5, 2023, with the first two episodes available immediately and the rest airing on a weekly basis through June 30.

## Reception
### Critical response

For the first season, the review aggregator website Rotten Tomatoes reported an 88% approval rating with an average rating of 7.6/10, based on 68 critic reviews. The website's critics consensus reads, "With deft writing, awe-inspiring production design and the inestimable star power of Rebecca Ferguson, Silo is a mystery box well worth opening." Metacritic, which uses a weighted average, assigned a score of 75 out of 100 based on 20 critics, indicating "generally favorable reviews".
Richard Roeper of Chicago Sun-Times wrote that the series "holds our interest with intriguing characters and effective twists and turns", and took note of how Silo "shifts gears through a number of genres, from conspiracy thriller to big-picture social commentary to police procedural to end-times romance". Lucy Mangan of The Guardian opined that the "world-building is meticulous" and "the story is equally thrilling". Vanity Fair's Richard Lawson found the show to be a "feat of production design", adding that "Ferguson—in all her stern command—lends the series a necessary heft". Barry Hertz of Globe and Mail also picked up Ferguson's performance as a "standout".
Conversely, Brian Lowry of CNN believed that the "inherent mystery [...] feels stretched to the point of strained, exacerbated by characters that don't consistently pop". The Hollywood Reporter's Daniel Fienberg also praised the world-building and Ferguson's performance, but was critical of the performance of Common, whom he termed "the weak link in the cast".
For the second season, Rotten Tomatoes reported a 96% approval rating with an average rating of 7.85/10, based on 44 critic reviews. The website's critics consensus reads, "Rebecca Ferguson's intrepid hero seeks answers while the rest of Silo's ensemble capably holds down the fort in this superb sophomore season." Metacritic assigned a score of 80 out of 100 based on 12 critics, indicating "generally favorable reviews".

### Accolades

| Year | Award | Category | Nominee(s) | Result |
| 2024 | Art Directors Guild Awards | Excellence in Production Design for a One-Hour Fantasy Single-Camera Series | Gavin Bocquet (for "Machines") | Nominated |
| 2024 | Black Reel Awards | Outstanding Guest Performance in a Drama Series | Rashida Jones | Nominated |
| 2024 | British Academy Television Craft Awards | Best Original Music: Fiction | Atli Örvarsson | Won |
| 2024 | British Academy Television Craft Awards | Best Production Design | Gavin Bocquet, Amanda Bernstein | Won |
| 2024 | British Academy Television Craft Awards | Best Costume Design | Charlotte Morris | Nominated |
| 2024 | British Academy Television Craft Awards | Best Special, Visual & Graphic Effects | Daniel Rauchwerger, Stefano Pepin, Richard Stanbury, Raphael Hamm, Ian Fellows | Nominated |
| 2024 | British Society of Cinematographers | GBCT Operators Award - Television Drama | James Layton and Justin Hawkins | Won |
| 2024 | British Film Designers Guild Awards | Best Production Design – TV Band 3 & 4 Programmes | Amanda Bernstein, Gavin Bocquet, Phil Harvey | Won |
| 2024 | Hollywood Music In Media Awards | Best Original Score - TV Show/Limited Series | Atli Örvarsson | Nominated |
| 2024 | Royal Television Society Craft & Design Awards | Costume Design - Scripted | Charlotte Morris | Nominated |
| 2024 | Saturn Awards | Best Science Fiction Television Series | Silo | Nominated |
| 2024 | Saturn Awards | Best New Genre Television Series | Silo | Nominated |
| 2024 | Saturn Awards | Best Actress in a Television Series | Rebecca Ferguson | Nominated |
| 2024 | Satellite Awards | Best Actress in a Drama or Genre Series | Rebecca Ferguson | Nominated |
| 2024 | Society of Composers & Lyricists | Outstanding Original Title Sequence for a Television Production | Atli Örvarsson | Nominated |
| 2024 | Set Decorators Society of America Awards | Best Achievement in Décor/Design of a One Hour Fantasy or Science Fiction Series | Amanda Bernstein, Gavin Bocquet | Nominated |
| 2025 | Satellite Awards | Best Genre Series | Silo | Nominated |