Episodes 01

“Freedom Day”

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, but they are unable to conceive. During this time Allison learns subversive beliefs about the Silo from Gloria Hildebrandt, a fertility expert, and helps IT expert George Wilkins explore a forbidden hard drive dating 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; she offers as evidence her birth control implant that had not been removed. Allison declares that she wants to “go out”, and promises to clean the Silo’s external camera if the outside is beautiful. Following the Silo’s Pact, Allison is dressed in an environmental suit and exits on a one-way journey. Silo residents watch Allison clean the camera and then collapse, dead. Two years later, Holston investigates George’s death, and meets Juliette Nichols, an engineer who claims he was murdered.

Episodes 02

“Holston’s Pick”

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 crawls 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.

Episodes 03

“Machines”

Ruth and Sam trek down 144 levels to meet Juliette. Along the way, Ruth meets Juliette’s estranged father, Dr. Pete Nichols, and Juliette’s engineer friend, Martha Walker, for opinions of Juliette’s character. Despite the disapproval of Judge Meadows, head of Judicial, and Bernard Holland, head of IT, Ruth offers Juliette the role of sheriff. Juliette initially declines but changes her mind when she’s given Holston’s badge, which has the word “TRUTH” carved on the back. Juliette requests that Ruth allow the main generator to be switched off for repairs, which has never been done in living memory. At shutdown, the Silo’s screens briefly show a healthy green view of the outside. The Mechnical team successfully fixes the main generator. Before leaving for her new job, Juliette asks Martha to study a camera she found among George’s relics. Sam and Ruth confess their love for each other, before Ruth collapses with blood in her mouth.

Episodes 04

“Truth”

Ruth is dead; Sam 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, signs Juliette in as the new sheriff. Juliette asks Sam to help her investigate George’s death, in return for her helping him investigate Ruth’s death. Robert Sims, of Judicial, tells Sam that Judge Meadows is ready to remove Juliette as sheriff, but Sam tells him to let Juliette quit on her own. Later, Sam 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 flashback, Juliette leaves home at thirteen after the deaths of her mother, Hanna, and younger brother, Jacob.

Episodes 05

“The Janitor’s Boy”

Sam 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 Sam’s killer before Judicial picks a scapegoat. Juliette discovers that Doug Trumbull, who works for Judicial, planted evidence to frame resident Patrick Kennedy for Sam’s murder. Robert tells Doug that his father was supposedly a janitor but in actuality had a secret job that was crucial to the Silo’s survival. Robert kills Doug before he can be arrested, and Doug is posthumously blamed for Sam and Ruth’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 lights are stars. Martha shows Juliette that the camcorder’s technology is more advanced than what is typical and permitted in the Silo. Juliette retrieves one of George’s relics in the hopes of reopening the investigation into his death.

Episodes 06

“The Relic”

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. Robert 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 Ruth and Sam. Juliette and Paul 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: a children’s travelbook dating from before the Silo. While Juliette browses the book in her apartment, she is watched by a surveillance team that has numerous cameras all over the Silo, with equipment much more advanced than the rest of the Silo.

Episodes 07

“The Flamekeepers”

Robert is part of the surveillance team and monitors Juliette’s movements via the cameras. Juliette seeks out Gloria, who is being drugged on Meadows’ order. Despite Juliette’s offer to resign as sheriff, Meadows says she can’t lift the order. Paul 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, and whose members are being systematically wiped out. Juliette’s mother befriended Flamekeepers, but Juliette’s father obeyed orders to prevent Flamekeepers from having children. Juliette realizes that surveillance cameras are behind the Silo’s wall mirrors, and retrieves George’s hard drive from where Holston hid it in Gloria’s room. Robert’s raiders arrive at Gloria’s room to apprehend Juliette, who isn’t there.

Episodes 08

“Hanna”

Judicial searches the sheriff’s office for the hard drive but cannot find it. Juliette retaliates by using Paul’s knowledge of the Pact to temporarily arrest Robert. While Robert is in custody, Juliette searches his office and finds files on Hanna, Martha, 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 Martha. Bernard finds Juliette and reveals himself to be the true person in charge of the Silo, and responsible for Ruth and Sam’s deaths. Bernard and Robert 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.

Episodes 09

“The Getaway”

Juliette escapes and evades Judicial’s cameras. Paul investigates Juliette’s apartment and finds the children’s travelbook; he keeps one page but burns the rest. Juliette breaks into Robert’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. Robert and his raiders rush to the apartment, but Robert’s wife allows Juliette to escape. Juliette gets Patrick’s help with Danny, 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.

Episodes 10

“Outside”

Juliette has Danny broadcast the outside footage to the whole Silo, but the broadcast is quickly shut down by Bernard. Paul is questioned by Robert on his condition; Paul later tells his wife that they are making an exception so he can be sheriff. Juliette escapes to Mechanical, where she talks to Martha before being arrested. Bernard offers Juliette a deal: she will go out willingly, in exchange for learning what happened to George and ensuring that Mechanical will not be punished. Bernard shows Juliette footage of how George was arrested and jumped 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’s display shows the exact same video footage of a lush landscape from the previous cleaning; she realizes the deception, discovering that the reality is the desolate view of the Silo’s screens. Because Martha has arranged for the heat tape on Juliette’s suit to be good quality, instead of dying there, Juliette is able to walk out of the crater that surrounds the Silo’s camera and out of view of the Silo’s residents. The camera pans and zooms out, showing that surrounding the Silo’s crater are dozens of similar craters, each with a structure similar to a silo entrance.