Warning: This article contains spoilers for Stranger Things season 4.
The band comprised of James Hetfield, Lars Ulrich, Kirk Hammett, and Robert Trujillo said they were "blown away" by the scene in the season finale, calling it an "incredible honor to be such a big part of Eddie's journey."
In the climactic scene in the Upside Down, Eddie (Joseph Quinn) and Dustin (Gaten Matarazzo) are used as bait to distract Vecna's (Jamie Campbell Bower) legion of demo-bats so Nancy (Natalia Dyer), Steve (Joe Keery), and Robin (Maya Hawke) can sneak into the villain's lair, the Creel house.
Metalhead Eddie ("This! Is! Music!") picks up his trusty guitar and shreds the 1986 track, successfully luring the creatures away from the Creel house. Following the release of Volume 2 Friday, Metallica shared a snippet of the big scene on Instagram Tuesday and geeked out over the inclusion.
"The way the Duffer Brothers have incorporated music into Stranger Things has always been next level, so we were beyond psyched for them to not only include 'Master of Puppets' in the show, but to have such a pivotal scene built around it," the band wrote. "We were all stoked to see the final result and when we did we were totally blown away."
The band continued, "It's so extremely well done, so much so, that some folks were able to guess the song just by seeing a few seconds of Joseph Quinn's hands in the trailer!! How crazy cool is that? It's an incredible honor to be such a big part of Eddie's journey and to once again be keeping company with all of the other amazing artists featured in the show."
Tina Rowden/Netflix Joseph Quinn as Eddie Munson in 'Stranger Things 4'
The track re-entered music charts following the finale, following the same resurgence of Kate Bush's 1985 "Running Up That Hill" featured prominently in Volume 1's "Dear Billy" episode, which included a standout performance by Sadie Sink. Quinn, who has played the guitar since childhood, recently told EW that he didn't record the guitar riffs himself, but he did play along with it during filming.
"We had a backing track and I was playing along with it," Quinn said. "I wouldn't wanna mess with what they've already got, but it was very useful to be able to play along character-wise. It's a pretty adolescent fantasy to be a rockstar, isn't it? I felt like one for a night. It was great having Gaten up there with me. They really turned it up when they played 'Master of Puppets' and the whole crew were there."
Quinn said it felt like a celebration despite his character's looming fate. "It was the first time that everyone felt like they were seeing live music — I say 'live music' — since the pandemic," he said. "So it felt like a real celebration."
EW's Ultimate Guide to Stranger Things is available online or wherever magazines are sold.