Who Is Dr. Kay? What to Know About '80s Icon Linda Hamilton's Mysterious 'Stranger Things' Role

This story contains minor spoilers for the first four episodes of Stranger Things season 5. Does it feel like forever since we were last in Hawkins, Indiana, running up that hill to save ourselves from Vecna? Well, the wait is over: Stranger Things is officially back.

The hit Netflix series unleashed the first four episodes of season 5 on Wednesday, November 26, finally giving fans the chance to see what’s next for the show’s young heroes and chilling monsters. While it’s a thrill to see all those familiar faces again, several new characters come into the fold for these final episodes. Among them is none other than Linda Hamilton, the latest ‘80s icon to make their mark on the show, following fellow stars of that era like Winona Ryder, Cary Elwes, Sean Astin, Robert Englund, Matthew Modine, and Paul Reiser.

If you’re curious to learn more about Hamilton—not to mention Dr. Kay, the government scientist she portrays in Stranger Things Season 5—tune your radios (this does take place in the ‘80s, after all) to the dispatch we’ve got below.

Who is Linda Hamilton, the latest '80s icon to join 'Stranger Things?'

Linda Hamilton, 69, is an American actress who built her career playing strong female characters, most famously Sarah Connor in the Terminator franchise.

Hamilton was raised in Salisbury, Maryland, and went on to study in N.Y.C. under the famed acting teacher Lee Strasberg. She made her acting debut in 1979’s Night Flowers and appeared in several TV series before landing her first leading film role in 1982’s Tag: The Assassination Game. Two years later, she’d portray Connor for the first time in The Terminator, changing the entire course of her career. “Did I think I was going to become an action-adventure star? Not once!" she told The New York Times in 2019. “I was going to be a Shakespearean actress, and with Terminator, it all took a left turn.”

In addition to playing Connor in The Terminator (1984), Terminator 2: Judgement Day (1991), and Terminator: Dark Fate (2019), Connor has appeared in films including Children of the Corn, Dante’s Peak, and King Kong Lives, and TV series like Beauty and the Beast, Chuck, and, most recently, Resident Alien.

Hamilton has been married twice: to actor Bruce Abbott and then to director James Cameron, who helmed the first two Terminator films. She has one child from each marriage, both of which ended in divorce. Hamilton has also been open about her experiences with depression and bipolar disorder after first speaking publicly about it in 2004. In a recent August 2025 interview with PEOPLE, she noted that her action-star movie roles make people assume she’s invincible off-screen, too. “Nobody ever thinks that I'm going to struggle,” she said. “[They think] I'll be fine—‘It's Linda Hamilton.’ ”

What made Linda Hamilton’s Sarah Connor so iconic in the 'Terminator' movies?

Sarah Connor has gone down in film history as one of the earliest and most enduring female action heroines. She arrived on the heels of Alien’s Ripley (Sigourney Weaver), Star Wars’s Princess Leia (Carrie Fisher), and the titular Foxy Brown (Pam Grier), and paved the way for defining female characters to come, from Demi Moore’s G.I. Jane to Kill Bill’s Bride (Uma Thurman) to The Matrix’s Trinity (Carrie Ann Moss), to, more recently, Marvel Cinematic Universe’s Black Widow (Scarlett Johansson) and The Hunger Games’s Katniss Everdeen (Jennifer Lawrence).

But Sarah doesn’t start as a hardened action hero. In the first Terminator film, she’s an everyday college student and waitress, until she’s targeted by a time-travelling cyborg (famously played by Arnold Schwarzenegger) to stop her from giving birth to a son destined to save mankind from a robot apocalypse. Over the course of the film, she goes from the damsel in distress to a woman forced to fight back in the face of impending danger.

The sequel, Terminator 2: Judgement Day, levels Sarah up even further. This time around, Sarah transforms herself into a relentless, hardened fighter, fiercely protective and willing to do whatever it takes to save her son (and humanity itself). The film became the highest-grossing film of 1991, and the image of Sarah’s unflinching, gun-toting persona—and toned biceps—became synonymous with the film franchise and Hamilton herself.

Sarah was killed off-screen in the 2003 film Terminator 3: Rise of the Machines, which didn’t rise to the same box-office success as its predecessors. Other actors have played the character over the years, including Game of Thrones alums Lena Headey in the 2008 TV series Terminator: The Sarah Connor Chronicles and Emilia Clarke in the 2015 film Terminator: Genisys, but it wasn’t until 2019 that Hamilton returned to the franchise in Terminator: Dark Fate. That film, directed by Tim Miller and set 25 years after the events of Terminator 2 (thus ignoring the other sequels), sees Sarah team up with a human-machine hybrid (Mackenzie Davis) to protect a young woman (Natalia Reyes) being hunted by Terminators.

“Just as a function of age, I can’t be the same Sarah Connor. I spent a year filling in the blanks, working with myself mentally and emotionally to get to my darkest places, my greatest sorrows, and disappointments, because that’s pretty much what she’s lived in for 25 years,” Hamilton told Forbes in 2020 of returning to play the character again, more than three decades after the first Terminator film. “I think an audience should be surprised when a major iconic character returns to the screen. That’s what made the difference between the first and second Terminator movies so special. She ain’t what you expect when Judgment Day opens, and I wanted to do that again.”

Who does Linda Hamilton play in 'Stranger Things' Season 5?

In Stranger Things, Hamilton isn’t a hero in the mold of Sarah Connor—this time, she’s among the antagonists hunting down our heroes. She portrays Dr. Kay, the new head scientist overseeing the military occupation set up in Hawkins, and taking on the work of Dr. Brenner (Matthew Modine) following his apparent death in season 4.

Dr. Kay is a calculating and unflinching adversary for the gang. She’s determined to capture Eleven (Millie Bobby Brown), who she thinks is a threat—and wants to bring her in alive. She may also be housing some sort of mystery on the military base, which will surely be explored in the season’s next two parts, set to arrive on Christmas Day and New Year’s Eve.

Series creators Matt and Ross Duffer praised Hamilton as a “legend” on the Stranger Things season 5 premiere red carpet, with Ross explaining that she’s stepping “into the government role” just as Modine and Paul Reiser (who played Dr. Sam Owens) did before her. “We wanted someone else of that stature, but what we liked about Linda is she’s obviously very sharp and intelligent, but also, she’s a badass—she can wield a gun, she can get in fights.”

The showrunners also hinted at what fans can expect from her role. In an interview with Entertainment Weekly, Matt described Dr. Kay as having an "unhinged quality." He said, "Part of the reason she's scary is that she, unlike Dr. Brenner, has no emotional connection to Eleven. There was that paternal quality that Brenner had. Dr. Kay has none of those feelings. She really views her just as a weapon that needs to be acquired."

Hamilton, meanwhile, was cryptic about her character’s motives. “She has an agenda,” the actress teased at that same November premiere event. “She’s the head doctor/scientist for the military, she’s trying to stop the madness in her own way, and she’s a force to be reckoned with.”

While she remained tight-lipped about her character’s intentions, the actress has been vocal about how thrilled she was to join Stranger Things. She told Variety that she’s been a fan of the series since it premiered in 2016 and essentially delayed retiring from acting to appear in the final installment. However, Hamilton joked that being on the show also “steals [her] joy” because she doesn’t watch her own work, so she can’t tune into the last episodes herself.

“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,” she told the outlet. “It’s such a feast to watch this show. 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.

The Hollywood legend added, “To build it is great. I’m as happy as I’ve ever been, just so happy to be part of it.”