Silo season 2 episode 9 ending explained: What could the Safeguard be?

After Juliette (Rebecca Ferguson) nearly died in Silo 17 and discovered that she and Solo (Steve Zahn) weren't the only people living there, Lukas (Avi Nash) went through a series of jaw-dropping discoveries.

First, that the founders didn't only build one silo but 51, and that all IT heads and their shadows know about the other silos.

He also comes across something called the Safeguard in the coded letter from Quinn that Bernard (Tim Robbins) is so keen to demystify, with it coming back to haunt him at the end of the episode.

So, what exactly is the Safeguard? Here's our theory based on the books – but be warned, it includes some big spoilers for anyone who hasn't read Hugh Howey's Wool trilogy.

**Potential spoiler warning for Silo season 2 and spoilers for the Wool novels**

Silo season 2 episode 9 ending explained: What could the Safeguard be?

The meaning of the Safeguard hasn't been confirmed in the show and this word isn't actually used in the Wool novels, so there's the possibility that it's an entirely new concept.

But, if the TV series is staying true to the storyline in the books, it's possible that the Safeguard could refer to the protocol that Silo 1 has oversight and control over the rest of the silos – and even the power to exterminate them if a rebellion gets out of hand.

It's just speculation at this point as to whether this is what the Safeguard refers to – although how the Safeguard is threatened by the mysterious voice does make it seem likely. Could the lives of the 10,000 people in the silo now be even more in danger than before?

Episode 9 sees Lukas decoding Salvador Quinn's letter, which leads him to the bottom of the silo. There, he discovers a tunnel.

A mysterious voice tells him that, before him, only three people had reached the tunnel: Salvador Quinn, Mary Meadows (AKA Judge Meadows, who was killed by Bernard earlier in the season), and George Wilkins (Juliette's boyfriend, who mysteriously disappeared).

The voice says he didn't speak to Wilkins, but Quinn and Meadows were both told the same thing as Lukas: "If you speak to anyone about this conversation or what you have seen down here, we will have no choice but to initiate the Safeguard."

When asked if he knows what the Safeguard is, Lukas responds: "I do," before the episode ends.

We'd expect the final episode of the season to show us more about the Safeguard and confirm how faithfully the series is following the books on this front.

Who could Lukas be speaking to?

Again, the identity of who Lukas is speaking to is not confirmed in the show. But, using the books as our guide, it's likely he's speaking to the managing authority in Silo 1. We don't know who specifically at this point.

Silo 1 is explored at length in the second novel in the trilogy, Shift, and it's likely that future seasons of the show will delve into the origin story of the silos.

Silo season 2 is available to stream on Apple TV+ - you can sign up to Apple TV+ here. Hugh Howey's Wool Trilogy is available to buy now.

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