Mystery box formats pose challenges for both creators and performers.

Silo is a complex series that even its showrunner finds challenging at times. During the filming of the final seasons of this Apple TV sci-fi thriller, Graham Yost recalls two moments where he stumbled on details: once, an actor pointed out that a conversation they were about to film should have already occurred, and another time, the Japanese localization team flagged a subtitle that didn’t align with the on-screen action. Both issues were resolved, but Yost’s reaction was the same: “Oh shit, you’re right.”

As Silo approaches its final two seasons, keeping track of everything has become even more daunting. Thankfully, Yost has a dedicated team helping to catch those mistakes. “It’s a lot to keep track of, but everyone is pitching in,” he shares, “and I love this sense of collaboration.”

Season 3 of Silo premieres on July 3rd and significantly broadens the narrative. The series centers on the inhabitants of a vast underground bunker set hundreds of years in the future. This silo houses 10,000 people living in a vertical city, divided into layers, each with distinct jobs and cultures, from the mines below to the government above. The only way to traverse the silo is via a massive spiral staircase, which symbolizes a stark class division.

Initially, it appeared that the residents were the last survivors of humanity in a post-apocalyptic world. However, the first two seasons revealed that they are just one of many silos, each containing its own isolated community. Season 3 introduces a new element: exploring how the world ended up this way, starting from a reality that resembles our own.

The premiere of Season 3 frequently shifts between the grim future we’ve seen and the present day, where the choices that led to the underground confinement were made. The story picks up with protagonist and reluctant revolutionary Juliette (Rebecca Ferguson), who has just become the first person to travel between silos and is now grappling with memory loss, complicating the already intricate narrative.

The cast employs various strategies to navigate these challenges, especially since scenes are rarely shot in chronological order. For some, daily meetings with directors are crucial. “A lot of days, we’d start the day with story time, and the director would go through where we’re at, where we just came from, what happens next,” explains Alexandria Riley, who portrays Camille Sims. “It’s already a complicated story anyway, but then when shooting out of order, you do get a bit foggy.” Ferguson adds that the hair-and-makeup team plays a vital role in maintaining continuity, as they need to keep track of details like scars and burns. “The little changes that you do have enormous ripple effects going forward,” she notes.

“It’s a lot of pieces you’re trying to put together,” says Common, who plays Camille’s husband Robert. “It is our job to know where we are, but thank god we had support, too. There are times when I’d have to talk to Alex about something just to be reminded.” The two even held separate rehearsals to ensure they were on the same page.

Others took a different route. Jessica Henwick, who joins the main cast as investigative reporter Helen in Season 3, opted to only read her own scenes. “I’m a fan of the show, and I wanted to preserve that experience. I will watch Season 3 as a fan and see what happens. I don’t know what happens except in our storyline.” Henwick was so enthusiastic about her role that she explored the set, particularly the stairs, soon after being cast.

However, diving into the source material doesn’t always help. Silo is based on a trilogy of books by Hugh Howey; the first two seasons adapted the first book, while the final two will conclude the story. The adaptation has made significant changes, particularly in making Juliette a more central character and updating plotlines to address contemporary issues like AI.

“I started reading the books and quickly realized that wasn’t going to help, because the books are so different,” explains Ashley Zukerman, who plays a congressman in the present-day storyline. He found that focusing on the scripts and then trying to forget what his character wouldn’t know was more beneficial.

With two seasons remaining, Silo is racing toward its conclusion, aiming to tie up all loose ends. Yost mentions that the plan was always for four seasons, so the challenge has been fitting everything into a limited number of episodes. Since the final two seasons were filmed back-to-back, the team no longer has to juggle those intricate plotlines. While Ferguson will miss the experience, she admits there’s one aspect she’s relieved to leave behind.

“I fucking hated running up and down those stairs,” she confesses.