Silo season 1 ending explained: everything that happened in the epic finale

What happened at the end of Silo season 1? We break down everything that happened at the end of the slow-burn Apple+ TV dystopian drama.

Troubled Jules was left fighting a lonely battle and asking a lot of difficult questions, in season 1 of Silo. Mechanical engineer turned unlikely sheriff, Jules became part of the Silo's law enforcement, ending up on the wrong side of it herself. In the adaptation of Hugh Howey's novel series, none of the Silo residents knew how they ended up in the colossal underground metal bunker, or what had happened outside to make the air too poisonous to breath. 

Diligently living under the rules of The Pact, the underground community don't question the world before, and doing so can mean being sent outside 'to clean.' In an anxiety-inducing turn of events, life in the Silo unravels and protagonist Jules receives that very fate. But how and why did that happen, and just what is going on? Let's unravel it all - if you were confused by some of Silo's events, you definitely aren't alone. 

Silo ending explained

By the series finale, Jules and the viewers know that all is not as it seems in the Silo. However, she and the inquisitive minds looking for answers before her, have been scuppered by forces working in the Silo to keep everyone in line. Finally getting to see the footage on the hard drive George left for her, she wants everyone in the Silo to know the truth - the world outside isn't the bleak landscape transmitted to screens around their underground home, but filled with blue skies and flying birds - or is it...?

As a wanted fugitive, hatching a plan to allow thousands of residents to see the footage isn't going to be easy. Enlisting Patrick and Danny to help, the trio clamber through the rubbish chute to place signal boosters on as many levels as possible, to transmit the footage to the Judicial office. Momentarily, this plan works and the members of the monitoring team have the footage displayed to them while an apoplectic Mayor Holland shouts at them to look away - when Sims hesitates to follow this command, Holland pulls the connection plug and the screens go blank anyway. 

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Jules is then captured and defeated - Holland tells her she has no right to a Judicial hearing and is a threat to the peaceful future of the Silo. After a final chat with surrogate mom Martha, Holland does grant Jules the final wish of letting her know what really happened to George. After being so sure he was murdered by Judicial, it turns out George really had taken his own life to avoid being tortured. A devastated Jules is then measured for her cleaning suit, while crowds gather to watch her go outside.

Jules is in informed her birth was an accident and not part of the Silo's pre-determined breeding plan. This harks back to the beginning of the series, where Allison suggests only the unquestioning and compliant members of the community were permitted to have children. As a rebel, Jules' mother wouldn't ordinarily have been permitted to give birth, but somehow managed to have two children. Breeding another rebel, it's made clear to Jules that her accidental birth needs to be erased to ensure future compliance in the Silo.

Defiant until the end, Jules tells Holland she isn't afraid, and will definitely not clean once she gets outside. Ascending the steps to the outside, Jules does indeed walk right up to the cameras once outside and drop the cleaning materials on the floor - to gasps from the gathered crowds. As with Allison and Holston before her, the outside does indeed appear to Jules as a beautiful green landscape, full of life. She does however surprise everyone by reaching the point the others who went outside collapsed and died, miraculously making it past this point.

During her final moments with Jules, Martha managed to bind the cleaning suit with the extra special tape that Jules had been accused of stealing; this had made it air tight. The extra time this buys her allows her to take out the sheriff's badge she's managed to smuggle out with her. Putting it next to the grass, she notices a glitch and the grass doesn't behave the way it should with something placed on it. Jules realises the world she's being shown through the mask isn't what's actually out there. The beautiful but false image then disappears, and we see that the world really is a ruin, with grey skies and crumbling cities.

Not only that, but as she walks further into the wasteland and beyond anyone who has been sent out to clean before her has made it, she takes in the entrances to hundreds of other Silos on the ground before her. They aren't alone, and there are potentially hundreds of thousands of others living the same way Mayor Holland's Silo residents are. With that, Jules keeps on walking and the closing credits begin to roll.

But hold up - viewer paranoia throughout the series pointed us to believing the outside was habitable, with Silo residents were being led to believe it wasn't and shown misleading images of a wasteland. All along, the outside really was bleak and uninhabitable. So where did the relic hard drive footage of a green and perfect outside come from? And why were those sent outside to clean shown this as their final image? And why don't the hazmat suits protect them for long once outside - Jules had to have hers altered to prevent outside air getting in? Let's take a look at these questions.

What does the ending of Silo mean?

The ending of Silo means that the outdoors really is unsafe, and those sent out to clean are shown a hologram version of the world to ensure they don't see the other Silos. They are also sent out with their suits secured with the not-so-good tape that lets toxins from the air in, killing them before they reach the other side of the hill and see the other Silos. 

Martha worked out there wouldn't usually be so much fuss over some tape going missing - do you remember the huge furore over that tape? She realises its significance and the fact it will add super airtight security to clothing, in time to add it to Jules' suit to keep her alive for longer.

Author Hugh Howey has revealed a series of nuclear bombs first saw earth's inhabitants pushed underground into Silos. The bombs saw the world left uninhabitable for at least 500 years, with Silo season 1 taking place around 300 hundred years after the Silos were built.

In the books, once she finds the other Silos, Jules enters Silo 17 and finds the sole survivor of an uprising that took place there decades before. The man, Solo, reveals to Jules how to communicate with the other Silos, and she finds that her former mechanical colleagues initiated a rebellion in her previous Silo once she left. Silo 1 has authority over all Silos, and if a rebellion takes control Silo 1 will exterminate all inhabitants of the rioting Silo. Being armed with this information is the reason Judicial in Jules' Silo will go to any lengths to prevent questions being asked, and maintain control of the population at all times. 

What is The Syndrome in Silo?

The Syndrome is a neuralgic response to living underground in unnatural conditions. Billings begins to display symptoms of The Syndrome, predominantly hand tremors and loss of balance. It is something he wants to be kept hidden from the authorities at all costs. 

A sign in the mechanical department can be seen reading: "The Syndrome Do you know the signs?," suggesting symptoms are "Involuntary twitching is the first sign, leading quickly to shaking of the extremities, flashes of pain and muscle spasms are next. Balance and movement is severely impaired. If untreated infection will attack the brain, resulting in reduced cognitive function and finally, A shut-down of the entire nervous system."

Per Screen Rant, Silo creator Graham Yost, said "Human beings weren't meant to live like this. Talking about that with Hugh [Howey], we came up with something called 'the syndrome'. It's a neuralgic response to the pressure of living in these conditions." Although not an expansive explanation, this could imply The Syndrome is caused by something such as a vitamin D deficiency (which could cause similar symptoms to Billings') or a mental health response to living underground.