Stranger Things creators admit they started filming season 5 without a finished script for the finale: "That was scary"

In an admission that will almost certainly prove to be a lightning rod for naysayers, Stranger Things creators Matt and Ross Duffer admitted they started filming on the fifth and final season without locking in a finale script.

"We went into production without having a finished script for the finale. That was scary because we wanted to get it right. It was the most important script of the season," Matt Duffer said on Netflix's new documentary One Last Adventure: The Making of Stranger Things 5.

From there, the behind-the-scenes documentary reveals a creative back-and-forth between both Duffer brothers surrounding Eleven's fate in the final episode.

"The whole episode has to be building towards, 'Eleven is going to kill herself'" Ross Duffer said in one moment.

Matt Duffer countered, explaining that constant rug pulls in the situation might exhaust the audience. The solution, according to Ross (and something that made its way into the Stranger Things season 5 ending) was to "keep it ambiguous."

The documentary, given a release by Netflix on January 12, also highlights more touching moments, including the main cast's on-set goodbye after filming had wrapped. But with the amount of discourse surrounding the finale (and, of course, #ConformityGate and the extra episode that never was), the Duffers' admission here is one that will grab the headlines.

Elsewhere, the pair have been talkative about much of the finale. They have confirmed their intentions to have Vecna swap sides at one point, with a final battle featuring Demogorgons also floated. There were even original plans to pen a three-hour finale – which perhaps led to delays in getting the script finished in time.

For our full verdict, be sure to read our Stranger Things season 5 review. Then dive into our picks for the best shows on Netflix.