To create Vecna’s terrifying and surreal landscape, series director and executive producer Shawn Levy chose to use a mix of constructed sets and CGI. “We always try to combine real art department constructed environments with these digital elements,” Levy explains to Netflix. The director’s reasoning behind this decision is twofold. “The more you practically build, the more you’re helping the actor do their job, but you’re also helping the audience with kind of an on-ramp to believability,” Levy says.

Sadie Sink definitely agrees with Levy’s first point. “It feels real, like the stakes are really high,” the actress said of shooting her battle with Vecna in “Stranger Things 4.” Vecna’s Mind Lair “was not the easiest set to film on,” she admits. “But I mean, it looks amazing.” Some of the more challenging practical elements of the set included “how slippery the ground was, and how careful I had to walk on it,” Sink recalls.

However, some of the digitally rendered set-pieces presented a challenge as well. For instance, Sink had to pretend she was being restricted by Vecna’s vines, which were added in later by digital artists. “We wanted the vines themselves to almost echo the flesh monster from season 3,” Levy explains. This texture was easier to mimic through computerized visuals than through practical effects.