Stranger Things ending after 10 years has many fans craving more of the sci-fi world they weren’t ready to leave.

A theory known as Conformity Gate, that claimed a secret extra episode was yet to come, bubbled up on social media after the final episode was released earlier this month.

While the fan-theorised second finale has not materialised, a behind-the-scenes documentary showing how season five of the hit TV series came to life hopes to satisfy some of those yearnings and burning questions.

Martina Radwan, the documentarian behind One Last Adventure: The Making of Stranger Things 5, tells BBC Newsbeat she found the Conformity Gate theory to be “a little bizarre”.

“Why would they withhold that?,” she asks.

However, she understands it can be “hard to say goodbye” for fans who’ve been on this journey for the past decade.

She hopes the two-hour documentary can offer some closure, while also providing a unique insight into the writer’s room and production process.

The Duffer Brothers, who created the 1980s-inspired, monster-infused inter-dimensional series, faced incredible pressure when tying up the beloved show.

This stress becomes all too real in the documentary when the brothers and their writing team are still working on the final episode’s script when filming commences.

It’s a revelation that shocked some fans.

But on a project of this scale, Martina explains, “you can’t write everything ahead of time” and it’s normal practice in TV and film to write while shooting.

“I think having access to the writer’s room is a real gift and a privilege that the brothers gave us because I think it’s very easy to think when you write a script, you literally just sit there and write,” she says.

“And it’s like: ‘No, it’s really thinking about a gazillion things, how you interweave all these stories’.

“I mean, this is a massive ensemble cast and to cover 19 character developments, it’s quite a feat and an accomplishment.”

In the documentary viewers see some of the debates the writers had, including whether creatures should appear in the final fight scene against Vecna and the Mind Flayer, as well as the ultimate fate of the lead character Eleven, played by actress Millie Bobby Brown.

It also shows how the main cast has grown over the years as characters and actors, by showing clips of their audition tapes and scenes from the first series, which aired in 2016.

“It was important to really show the longevity and also how everybody developed individually, but also with each other as a group,” says Martina.

A standout element of the documentary is how it showcases the scale of the series’ production.

Hundreds of creatives, cast and crew work tirelessly to create a realistic Hawkins, Upside Down and Abyss to a tight deadline and, at times, without a complete script.

“That pressure on a show that is so beloved and so big is immense,” says Martina.

“I don’t know how the Duffers are doing it, to be honest.

“I love that everybody’s like: ‘We don’t know how to do this, this is impossible’, and then they turn around and they do it.”

In his wrap speech featured at the end of the documentary, co-creator Ross Duffer reveals season five took 237 days to film and says 6,725 set-ups were used to create 630 hours of footage, which was later edited down to about 10 hours.

Martina says she approached the documentary wanting to illustrate how a project of this scale is made because it “does all these things that nobody thought a TV show can do”.

This was also the Duffer Brothers’ intention as it was watching behind-the-scenes documentaries of classic films, like The Lord of the Rings, which inspired them when growing up.

Snippets of homemade films the two made as children reflect their lifelong passion for film-making, as well as an interview with their former drama teacher, who has a cameo role in season five.

“They didn’t become successful overnight, this is 40 years in the making process,” Martina says.

“They started making feature-length movies at the age of eight. So, to me, the core of it is that they really represent everything that I love about film-making.

“And also, they’re true to their art, they’re true to their vision, which I really admire as a director myself.”

– One Last Adventure: The Making of Stranger Things 5 is available on Netflix.

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