Yes, That Was Linda Hamilton in “Stranger Things” Season 5

Linda Hamilton has entered the Stranger Things universe.

The beloved action star, perhaps best known for her performance as Sarah Connor in The Terminator series of films, has made her debut in the first batch of episodes that dropped from season 5 of Netflix’s hit series.

Hamilton, 69, joins the cast as antagonist Dr. Kay, a military scientist hunting down Eleven (Millie Bobby Brown). Kay makes her series debut in the premiere episode, “Chapter One; The Crawl,” but her involvement in the series has been long-teased ahead of the release of Volume 1 on Nov. 26.

“She’s got a special agenda there that is kind of withheld throughout most of the season,” Hamilton previously told Netflix’s Tudum. “And that’s all I can say about that. But she was great fun to play. They gave me some good stuff to do. Got to mix it up a little bit.”

Hamilton’s first scene shows her dissecting a creature from the Upside Down that doesn’t bite “but does strangle.” She’s annoyed by a sergeant who tells her they failed to capture Eleven. “Please tell your commander that I am running into a wall here,” she tells the sergeant. “People are dying, innocent people. I need the girl.”

Hamilton’s arrival in the franchise comes nearly a decade after it first launched on the streamer in 2016. She told Variety that she’s been a fan of the show “from the beginning” and that her Stranger Things love “never subsided.”

As she recalled, Hamilton phoned her agent a month before scoring the role and floated the idea of retirement (due, in part, to “a really bad hip problem” and travel schedules). But then she got the call about Stranger Things.

“There’s a part of me that would almost rather watch it than be in it, because now that I’m in it, I won’t get to see it,” Hamilton told Variety. “I don’t watch my work. I cannot separate myself and my critical inner person from just someone that’s enjoying watching it. And it’s such a feast to watch this show.”

She added, “So during our script readings, I am watching everything, because I’m never going to get to see it on the screen and to watch it unfold.”

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Matt Duffer described the character of Dr. Kay to Empire as “hyper-intelligent and intimidating,” as well as a scientist who knows how to “shoot a gun.”

While she’s technically “the last one to arrive at the party” in terms of casting, as she told Tudum, Hamilton had “great fun” on set despite it being “a little nerve-wracking at first.”

Season 5 of Stranger Things kicks off in the fall of 1987 after Vecna “vanished” with his “plans unknown,” per an official synopsis from Netflix. It marks the show’s newest installment since season 4 concluded in July 2022. It also marks the end of the series.

Brown, 21, told PEOPLE at the season premiere in Los Angeles on Nov. 6 that building a family from the show since its debut is “probably the most amazing part about” the experience. “It’s taught me a lot of lessons about being a professional person, about being an actor, about being a friend,” she said. “It’s given me the most amazing people in my life to call up when I need them most, and that’s my family.”

Stranger Things season 5 Volume 1 is now available to stream on Netflix. It will be followed by Volume 2 on Dec. 25 and the finale on Dec. 31.