Linda Hamilton, widely recognized for her iconic role as the fiercely protective mother in the Terminator series, has taken on a new persona in the Stranger Things universe. This time, she’s swapped sides, portraying a gun-toting scientist.

The celebrated actress, known for her portrayal of Sarah Connor, makes a special guest appearance as Dr. Kay, a determined military scientist on a mission to find the telekinetic Eleven, played by Millie Bobby Brown.

At 69, Hamilton has joined the ensemble cast for the series’ fifth and final season. Her character, Dr. Kay, appears in the first four episodes, which Netflix premiered on November 26.

Viewers meet the no-nonsense Dr. Kay as she examines a creature from the Upside Down in the season’s debut episode, titled Chapter One: The Crawl.

“She’s got a special agenda there that is kind of withheld throughout most of the season,” Hamilton revealed to Netflix Tudum, offering a glimpse into her enigmatic new role.

‘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.’

Linda Hamilton plays gun-toting military scientist Dr. Kay (pictured) in the fifth and final season of Stranger Things 

Fans are introduced to the no-nonsense Kay as she gets to work during its opening episode, Chapter One; The Crawl (pictured)

The actress previously admitted to being a huge fan of the ’80s based science fiction drama following its initial launch on Netflix in 2016. 

‘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 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. 

‘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.’ 

Outlining Hamilton’s character ahead of the season five launch, show creator Matt Duffer revealed the government agent is a force to be reckoned with.  

‘She’s hyper-intelligent and intimidating,’ he told Empire in October. ‘She’s a scientist but if she needs to, she can get into a fight and shoot a gun.’

Hamilton’s casting was announced in June 2023, but it was more than a year later that she was first pictured on set, and since then her character has remained under wraps.

‘I couldn’t wait to tell people. I just couldn’t wait,’ she said of the role.

Hamilton is better known for playing Sarah Connor in the sprawling Terminator film franchise    (pictured in Terminator 2: Judgment Day)

The actress is pictured attending the Stranger Things season five world premiere in Los Angeles on November 6 2025

Hamilton’s casting was announced in June 2023, but it was more than a year later that she was first pictured on set, and since then her character has remained under wraps

In February, the Terminator star revealed that her casting in Stranger Things season five was a mixed blessing, as she loves the show but never watches any film or series she’s cast in

In February 2024, she revealed to Us Weekly that she was a huge fan of the series and had ‘watched every season with relish.

The actress also admitted that the show’s creators, Ross and Matt Duffer, had explained details about her character over a video chat session, but they had avoided sharing much of the final season’s plot in the hope of avoiding a potential leak.

‘It takes a lot of discipline to not know where it’s going to go. But that’s to protect it from all of the people that want to know,’ she said.

The actress reiterated her long-standing habit of never watching any film or television show that she appears in. 

‘When you really buy into something, you don’t see yourself in it,’ she explained. ‘So I think, in a way, it kind of ruined the show for me. I never watch [a project], once I’m in something.’

‘It would just completely take me out of the reality of it to see myself in there,’ she continued. ‘So I won’t be watching [Season 5].’