INTERVIEW
Cerys Jone | 21/12/2025
Linnea Berthelsen has always approached every role with consideration and emotional depth; in fact, it’s always been her first priority. When asked if there’s a single moment that inspired her to begin her career in acting, she says it's a mix of many. Having discovered her love for acting through community theatre, grounding herself and exploring the depth of each character has always felt personal and paramount. Berthelsen speaks openly about how she prepares herself, especially when it comes to Kali and the trauma she carries. While Kali may be one of the show’s most complex figures, Berthelsen remains committed to that complexity, with her love for acting at the heart of every movement, word, and portrayal.
Alice: What first drew you to acting, and was there a moment when you knew it was something you wanted to pursue?
Linnea: I thought about it, if there was a single moment that felt defining. But truthfully, I think there were many.
I was working backstage one summer on a community theatre production of Bye Bye Birdie in Pennsylvania when I was 17, and I was completely disarmed by the sheer joy that musicals brought to an audience, that was one moment.
I backpacked for 1,5 years when I was 18 and by the end of my trip, I got spend time in NYC and LA where I did my first acting class at the Barrow Group in NYC and in LA, I spontaneously did my first little audition, that was another.
But I think that ultimately, applying to drama school felt very defining. I was still debating degree options when a headmaster at one the schools at the third rounds of auditions asked me to make a commitment. That’s when I think it became clear to me.
I’ve always felt quite driven, and when I fell deeply in love with acting, I worried that I didn’t come into the industry with a childhood connection to the profession like a lot of my peers had. It had never been a hobby, I never acted as a child, so it’s always been a profession to me.
Alice: How do you approach building a character from the script?
Linnea: I definitely start with the script to find out what the material asks of you, a bit of a general theatre script analysis approach. What are the physical requirements? What is my function within the story? And then I try to build a bit of plan around that.
Matt and Ross’s script asked for quite specific physicality and required me to understand some fairly complex questions and concepts.
I was lucky that I had quite a lot of time due to strikes, so I got to work slowly and with both a brilliant PT in London for a year to balance that physicality, and a coach from New York (who works with Creative Dream Works) who I’ve worked with prior to this for years, to discuss everything with.
I’ve worked with a lovely group of coaches for 7-8 years, that I know really well by now, and I usually make some sort of plan with them and try out things as we build.
Alice: Has your acting process changed since your early roles?
Linnea: Definitely!
All the time. You’ll hopefully learn something every time you do a production or go into some training that you can bring back to the process.
And I get immensely inspired by fellow actors and try to apply some of their approaches to my work if I can.
Nick Offerman in DEVS (2020) was a pure masterclass in comedic precision and nuanced drama and his work completely blew my mind!
Alice: How do you balance instinct and preparation when stepping onto set?
Linnea: I prepare a lot. I drill a lot, both lines, but also physicality wise so that my body has somewhere to go as a default, and that sort of allows me to be more free within a scene.
I did gymnastics and contemporary dance for 15 years prior to acting, so there is a part of me that enjoys solid choreography as a baseline and treating it a bit like doing a piece of jazz music - learn the beats fully, to be able to be free.
The dream would have been to be a comedic genius of course - who can just ride the waves of a scene, but that definitely wasn’t on the cards for me!
Alice: How important is collaboration with fellow actors in shaping a performance?
Linnea: Very important, I think. We depend on each other, both cast and crew to shape our performances in all departments.
I come from a bit of a theatre and ensemble culture, so I honestly find it immensely helpful to collaborate, be present for each other's takes, (even just for those small moments) which this cast and crew are just exceptionally good at.
I think it grounds the work so much, and we get so much information from each other as we do the scene.
Alice: Is there a character you’ve played that stayed with you longer than expected?
Linnea: I think certain mannerisms from my character on Alex Garland’s DEVS stayed with me for a bit. Her way of taking up space was quite inspiring to me on a personal level.
But ultimately, I think once I stop “drilling” and playing a character regularly, the physicality likely leaves me, while other aspects may stay.
I was quite surprised that when I came back to work on Eight, the undercurrent of her grief and that guarded way she looks at the world was so easy to reconnect with.
Alice: What was your first reaction when you learned you’d be joining the Stranger Things universe as Kali?
Linnea: It was just wonderful!
I got the call from Matt and Ross Duffer on my way home from the screen test I remember, in the car from the airport. I lived in San Francisco at that point.
It was a wild couple of months, I was technically still in drama school, as I’d just deferred for a year to do a theatre performance. It was all just a bit mad and so lovely.
Coat, KULAKOVSKY @kulakovsky. Dress, OIZA @oiza.studio. Lingerie by Coco de Mer @cocodemeruk. Shoes, TOGA PULLA @togaarchives. Glasses, Poppy Lissiman @poppylissiman. Rings, Dinosair Designs @dinosaur_designs
Suit, KULAKOVSKY @kulakovsky. Bra, Viviano @vivianostudio. Rings, Daisy London @daisylondon. Glass earcuff, POND London @pond_london. Spike earcuffs, LAG World @lagworld. Boots, Charles & Keith @charleskeithofficial.
Alice: How much were you told about Kali’s backstory when you were cast.
Linnea: So, Kali was originally called Roman and was a 30-something -year-old man, so she has definitely changed over time.
I think because we shot S2 so fast, I didn’t have much to go on, which is also a lovely challenge of course.
I remember the buzz words from that brief such as “she had been in the lab and been hurt, and had been seeking revenge ever since”, but also that she was this sort of mirror of Eleven, of what she could have been, had she not met Hopper, Mike and her friends.
I think the reality is that we, and Matt and Ross know so much more now, and that in hindsight, maybe I didn’t know a whole lot about her, which is sometimes also helpful.
Alice: Did you feel pressure stepping into such a beloved show with an established fanbase?
Linnea: Of course! It’s such a lovely, passionate fanbase and a very beautiful thing!
However, I think, personally, I’m not really that tuned into that part of the show, so for better or for worse, I treat it as a lovely, technically challenging job, and then I leave that world for a bit.
But what a gift that fanbase is to the show!
Alice: Kali is intense, guarded, and emotionally complex—how did you approach creating her inner world?
Linnea: She really is, and I do think the inner world is so important to ground a character.
I think a lot of my job this season was to understand the duality and depth of the existential questions that fill her up. As I said earlier, I worked with a wonderful coach to really layer those concepts - not just on a conscious level, but also on a physical one. There is a heaviness to her that comes from the guardedness you talk about, and I think there is also a lightness to her that comes from the circumstances of this season; both need to be there.
And then I took a lot of inspiration from various harrowing accounts from Holocaust survivors (e.g. Mengele’s child victims), especially Andra and Tatiana Bucci who wrote a beautiful account on some of their memories called Always Remember Your Name. That made it possible for me to try and understand a key aspect of that child-like innocence, the view on war crimes and profound hope that I think Eight has.
I’m so grateful that we, as the public, have access to institutions like The Imperial War Museum in London where I visited, and access to brave writers who make it possible for us all to access places we couldn’t otherwise go to.
Alice: How do you separate or manage your own emotional well-being from a character who carries so much pain?
Linnea: I think the reality is that (in how I work at least), some of this work does hurt a bit. But I can protect myself through structure, communication and keeping it professional.
I often make it quite a technical exercise, in order to protect myself and I will need in those moments, for people to let me go through that process, rather than tending to my personal feelings if possible. It’s a lot to ask, but it helps.
And I was very fortunate that whilst working with the brilliant Frank Darabont and his amazing crew on some of the intense scenes this season, they tuned into this so brilliantly.
I’m eternally grateful to Frank for trusting my process and for the crew who knew when to leave me, and when I needed a bit of support, as they (quite literally) picked me up from the floor a few times after some of the scenes. The process was just extraordinary.
Alice: Kali’s sense of family is unconventional—how did that influence the way you played her relationships?
Linnea: I think, for whatever reason, that I really understand where she is coming from - the fear of not being unconditionally loved and how that affects every relationship in her life.
I don’t personally live that reality, but I understand the undercurrent of that fear within her, the slight hope that she carries, and the transactional relationship that she has to being loved. Which doesn’t come from being evil by any means, it comes from never having experienced unconditional love and her constantly - even at her lowest - trying to find a way to be worthy of that kind of love. Which I find quite heartbreaking.
Alice: When acting can depended on imagination and visual effects for parts of roles, how do you immerse yourself in it?
Linnea: Oh, good question. It’s a bit of constant learning finding these inner images and it only gets better with experience, I’m sure.
I think it may come back to specificity? Trying to be as specific as you can about what you’re seeing, and what your scene partners are seeing.
Alice: Did the show’s supernatural elements change how you approached realism in your acting?
Linnea: I honestly don’t think about the supernatural element at all.
It’s heightened of course (like a lot of theatre, Marvel), there is a specific tone there,
But honestly, I only ever think about the dramatic or comedic requirements of the scene and the tone of the show.
Alice: How did you and Millie Bobby Brown work together to build the bond between Kali and Eleven?
Linnea: I think, first of all, this is one of those surreal experiences, and I think Millie would agree here where you just happen to have great chemistry with your scene partner, for whatever reason, which is lovely!
But I also think there is a bit of unpredictability and a sense of care within our dynamic, that is both specific to Eight and Eleven, but also to our real-life relationship. I think it’s fantastic and shouldn’t be jeopardised if possible.
So, I think part of the process was both to build the trust to be able to do those scenes together, but another aspect I think, was to protect that very unique dynamic throughout the shoot.
And she’s incredible, and I will miss doing scenes with her. It was a very unique, professional partnership.
Alice: Do you see Kali as a cautionary figure, a mentor, or something in between for Eleven?
Linnea: I think, while she may have acted as a sort of cautionary figure for Eleven in Season 2, I think for Season 5, we start to see a change within this dynamic. We see how in reality, Eight is perhaps, even less emotionally mature and developed than Eleven, and that Eleven is also a mentor to Eight in some regards. They seem more equal in some ways in this season.
Alice: If Kali were to return, how do you imagine she might have changed? (I’m aware she is returning and you can’t say much so reworded it but feel free to leave)
Linnea: I think she is profoundly changed due to the circumstances she finds herself in.
She is in a form of regression I’d say due to what happens. So, I think we’re left with a quite raw version of her.
Alice: How do you decompress or reset after intense scenes?
Linnea: If I get to go home after, I’d love to do a deep rest, drink hot tea, go for walks to shake it off a bit.
If I’m lucky enough that we have a bit more work to go, I’ll see if I can do a quick re-set of my voice with teas and bubbling in my little straw and then have a rest or a lie-down meditation in the trailer.
Alice: Have you learned techniques over time to protect your mental health while doing emotionally demanding work
Linnea: I think that the biggest risk health wise for me, is that the work affects my personal life.
I try to prevent it by being fully prepped and being able to communicate my points well, to keep it a professional task, rather than something personal.
The other thing is - a shared effort indeed - which is just being kind and do your best to contribute to a kind working environment, even on your worst days.
This show has some of the kindest people I’ve ever met and I was able to do and enjoy doing some of my toughest work because of them.
Creative Ruben Davies @rubendavies
Photography Ruben Davies @rubendavies
Styling Millie Cullum @milliecullum
Styling Assistant Sophia Adatia @sophia.adatia
MUA Charlotte Yeomans @charlotteyeomansmakeup
Hair Styling Ana Lazovski @analazovski
HATC Alice Gee @alicesgee
Top, The Frankie Shop @thefrankieshop. Bangles & Ring, Dinosaur Designs @dinosaur_designs.
Dress, Hai @homeofhai. Skirt, Toga Pulla @togaarchives. Boots, Vagabond Vagabondshoemakers. Ring (left hand), Maison Lumiere. Rings (right hand), POND London (pond_london)
