[Warning: This story contains spoilers from the fourth episode of Black Mirror season three, "San Junipero."]

There's only one place in the Black Mirror universe that viewers would want to visit over and over, and that's San Junipero.

The 1987 California-set town, with its neon palette, nostalgic soundtrack and oceanside optimism, came out of nowhere for dedicated viewers of Charlie Brooker's dystopian anthology series. At the halfway point of its third season (which dropped on Netflix last month), Black Mirror time-hopped through decades to tell a feel-good love story that, unlike every other episode in the tech-horror series, came with a happy ending.

"San Junipero" mysteriously plays out like a star-crossed romance for young lovers Yorkie (Mackenzie Davis) and Kelly (Gugu Mbatha-Raw). Viewers eventually learn that San Junipero is "nostalgia" therapy and a virtual reality where the older and dying Yorkie and Kelly can visit by uploading their consciousness to a cloud. In the end, the just-married pair — who couldn't have legally wed in the real 1987 — spend the afterlife together in the simulated city, driving off in the sunset to Belinda Carlisle's "Heaven Is a Place on Earth."

The critically praised episode has been celebrated by viewers, who have taken to social media to cheer the '80s throwback and applaud the moving and hopeful story of two LGBT characters, a rarity on television. Thanks to Brooker, viewers are even listening to the episode's 42-song Spotify playlist.

As its popularity grows, so have alternate theories about "San Junipero's" ending. Speaking to The Hollywood Reporter, director Owen Harris confirms that Kelly and Yorkie do indeed spend eternity together, though he describes the factors lurking beneath their happy ending.

Harris, who also directed Black Mirror's season-two love story "Be Right Back," imagines how a parallel San Junipero could exist within Black Mirror and explains why anyone jonesing for a sequel should think twice: "Charlie Brooker might not want to do two happy endings!"

Read his full chat with THR below.

Stranger Things was the breakout of the summer and then here comes "San Junipero." Why do you think '80s nostalgia is resonating so strongly right now?

Films of the 1980s were the ones that I grew up with and I remember that it was a period in life that was really optimistic. Even if you’re sometimes dealing with darker subjects, there always seemed to be this strange optimism. I don’t know whether that had to do with the tone or the mood of the time, or the cinematography. Or just the way people were approaching and looking at life. But there was a strong sense of optimism and that's at the heart of the idea.

As we spoke about, Netflix viewers could use some optimism in the current political climate — post-Brexit in your U.K. and post-election here in the U.S.

Yes. "San Junipero" is this world where you’re allowed to dance around to Belinda Carlisle, it’s a world of guilty pleasures. Because of the look and the feel of it it’s larger than life, which makes everything a little bit more hopeful.

You filmed this heaven on earth in South Africa. What went into pulling off a '80s California in Cape Town?

Lots of head scratching! Quite early on we found a street, which we used as the street outside the club. Kelly’s beach house was on this beach that we found in the middle of nowhere that was stunning. The amazing thing about Cape Town is that it has these really rich, beautiful settings. The drives and all the bits between. Suddenly you could create a version of California that felt slightly heightened because of this slightly strange quality. We were shooting the scene where Kelly and Yorkie are both in their wedding dresses and have the argument while looking out across the city and this incredible mist rolled in from the ocean and it turned into this really beautiful scene. It had some challenges, but it gave us some really lovely texture.

The soundtrack is spreading like wildfire. What was the process for picking the songs?

It was a mixture of script and then having fun with it. There were numbers that were scripted, certainly the Belinda Carlisle track, as Charlie tonally wanted to place them in the decade. But then we all had a load of fun going back to our guilty pleasures and ‘'80s playlists. Robbie Nevil's "C'est La Vie," which plays in the beginning, that was one of the first singles that I ever bought. I thought I must have bought it for a good reason, so I listened to it again and it’s actually a great track! The baseline and everything.

Viewers are conditioned to expect the worst from an episode of Black Mirror, instead you gave them an eternal love story. How do you feel about the end?

What’s nice about Black Mirror is in the end, they always end up subverting everything slightly. They always give you a slightly different take on everything. Even though you’re left with this uplifting, optimistic feeling, beneath the surface there is something slightly lurking in terms of the decisions that we do make. It asks the questions: What would you do? Would you choose San Junipero? It’s working on different levels.

So, basically, nothing in Black Mirror, even San Junipero, is a total happy ending?

I guess it's bittersweet — more sweet than bitter. But in the end, we’ve learned a lot about Kelly and the decision she had to make, and the fact that she lost a daughter and her husband and now she’s going to spend a life with Yorkie. There’s something interesting in terms of choices and this idea of: Would you go there if other people that you loved weren’t able to join you there? On the one hand, it feels nice to feel good and uplifted and then if you want to ask yourself those questions you can do that as well.

One of the biggest fan conspiracy theories on the ending was that Kelly was a simulation in Yorkie’s mind (something Charlie quickly shot down). Were you surprised people had that reaction?

No, not at all. It’s a fun thing to play with expectations. The Black Mirror audience is constantly waiting for the twist while watching, so it becomes: How do you let that twist play out? By the end, you want to leave people with a sense of certainty about how they are feeling, but with a small tingling of something that isn’t quite right or that they need to ask themselves about. The fact that some people come to the decision that the ending is something different, that’s not a bad thing.

Did you ever toy with a different conclusion?

No we didn’t. That’s why it makes it such a nice piece because it felt like we’d be doing people out of a happy ending if we didn’t do it. In the opening, by setting up this 1980s world, there’s a promise of something good. And just like every film from the ‘80s, like Pretty in Pink and the John Hughes films of the time, even though you hit some big bumps on the way, you end up feeling good. That’s why using the ‘80s genre was a nice way to pay it all off. There’s some really big bumps that make it contemporary, but it still ends up with this nostalgic, feel-good feel to it in the end.

Giving a same-sex couple a happy ending also upended this year's Bury Your Gays trope on TV. Charlie said he wrote the pair as heterosexual, but changed it to richen the story. How did that decision impact your storytelling?

Charlie is really clever because it made Kelly’s reasons for wanting to try San Junipero all the more enticing. If you’ve lived an entire life with someone you’ve loved, that’s one thing. And you’ve had a family, that’s another. It can be very fulfilling to have all your great parts and your tragedies and all these things you live through as a couple. But if there’s a part of you that’s missing because you ultimately want something else, then that’s a big sacrifice you make. You don’t have to be gay to have those desires or regrets in life. But I thought it was a really nice way of exploring it. When I was making it, I almost instantly didn’t even think about it, ever. I suppose that comes down to how Gugu and Mackenzie played it, but you didn’t even think about whether they were straight or gay. They were just two people in love.

What most surprised you while directing Mackenzie and GuGu?

What they did so brilliantly is that they made you care about them. Once you discover that world is actually a generated world, when you then return to it you still care about them. That was the one thing I was really conscious about trying to pull off is that when you discover that these two are generated by these older women that you might stop caring about them. Because of the way Mackenzie and GuGu work together and the way you feel about them, you carry it all the way to the end.

Would you have chosen to go to San Junipero?

I definitely would have gone to San Junipero. I don’t know if I’d want to stay there forever. It’s a nice idea to go back to your mid-20s and hang out and have fun, and I suppose that’s the big question at the end: Do you want that to be yours forever? If I could take everyone I loved with me, and we could all go there and have fun — and I suppose that was the question Kelly was asking herself and made it even more difficult — it would be amazing!

Do you think there are other versions of San Junipero in the Black Mirror universe — could we see a sequel?

It’d be nice wouldn’t it? It’d be fun to do a San Junipero sequel. But you have to remember that if there is a sequel, Charlie Brooker will be writing it. He’ll go all Black Mirror on it and he might not want to do two happy endings!

What about a short version or spinoff?

I can guarantee in the next two or three years people will make their own versions of San Junipero and they’ll be on YouTube, they’ll be everywhere. But whether we make one, I don’t know. I would love to. If you think about it, once you buy into San Junipero it’s this big world and we got a little taste of it when she goes off into the Quagmire, where she tries to find Kelly and bumps into Wes, and that’s very dark place. That was a sort of splinter of Black Mirror. So there is always a dark side lurking. There’s probably lots of ground you could cover by that or a parallel San Junipero, wherever that might be.

"San Junipero" has a rewatchability factor unlike any other Black Mirror episode. What should people look out for when they go back for a second or third visit?

When you watch it for a second time, it’s incredible because there are so many hints. The challenge is that so many conversations make sense only in hindsight, but when you’re watching something you’re never watching it in hindsight. On the first run, they only slowly make sense. But when you go back, so many things the characters say are incredibly obvious. You’ll start to notice the little clues in most conversations. There’s a guy that chats Kelly up at the bar and he says something about how he has something wrong with his hip and how he should have put his money into computing. Suddenly you realize this must be a guy in his 70s. When you suddenly realize all of the people in this world are a different age.

How close are we to a San Junipero actually happening?

I suppose there are versions of it happening now. There is the 3D virtual world, Second Life, where you have an avatar of yourself and you go create a world and buy houses. A friend of my sister has a garage he’s set up with screens in it and he literally spends hours in there as his avatar wondering around. It’s terrifying. Absolutely terrifying. So there’s a basic version of it at the moment, but who knows? I can’t quite workout how that technology would work but it’s fascinating to think that it could.

Both of your Black Mirror episodes surround technology-created relationships. Where do you stand on love being real if it's computer generated?

They are strangely similar in that they have a very Black Mirror feel to them and technology is at the heart of it, but of all the episodes they’re both relationship-led. What was interesting about "Be Right Back" was the idea that online you give away a certain part of yourself. So if you had to try to rebuild someone purely on what they put on online on Facebook and Instagram and all these places where we portray an image of ourselves, you could potentially rebuild someone’s personality. But it would never be a complete truth and what she misses about her partner are all the rough edges and different parts to him. Can relationships exist in that way? I guess you have the honesty in a way, and the honesty is sometimes all the bad things as well.

Charlie is shooting the next six episodes for season four now. Are you returning to direct any?

They very kindly asked me about it but I’m already on something else. I love working with them and I would definitely do something again if they wanted. There are certain Black Mirrors where the scripts chime with me and for me. The balance between the Black Mirror discussion about life and technology felt really nicely balanced with the human story that you’re telling in "San Junipero" and "Be Right Back." Charlie writes really lovely pieces like that, so maybe one day I’ll do something else with him.

The third season of Black Mirror is streaming now on Netflix. For more of THR's show coverage, head here.