Inside 'Stranger Things' team's daring method to film finale

In a daring move, the Stranger Things team was filming the finale before the script was completed.

The new documentary, One Last Adventure: The Making of Stranger Things 5, gives insight into the making of the last season of the beloved sci-fi show.

Behind-the-scenes footage shows creators Matt and Ross Duffer can be seen commenting on having to film the show with an incomplete script.

"It's not like we don't know what the ending is. It's all plotted out," Matt can be seen telling the cast and crew.

"I have to write it, and we're just low on time," he added.

The documentary went on to show that even the finale, which was 2 hours and 8 minutes in length, had to begin filming with the script still incomplete.

In another scene, set production assistant Montana Maniscalco informed the camera, "We are shooting episode 8, which isn't completely written yet — spoiler alert! So we don't even fully know what's going on."

"I've never read 8 through, and we're just shooting it," Matt shared. "I've never done anything like this before. This is so weird jumping to eight... Don't love it. Don't love it."

The Stranger Things finale aired on 31st December and saw the group, which included David Harbour’s Hopper, Winona Ryder’s Joyce, kids El, Mike, Will, Dustin, Lucas, Erika, Max, as well as older adults Steve, Nancy, and Jonathan, fight Vecna and the Mind Flayer in a final battle.