No makeup, hair slicked back into a simple ponytail and a plain red T-shirt, Harriet Slater looks fresh-faced as she greets me with a cheerful smile.

Charmingly, she has accidentally muted herself on Zoom, bursting out in laughter as I tell her to switch on the microphone: “No! I’m sorry! Usually I forget to share my screen so I thought I smashed this,” she says. The warmth of her personality shines through immediately, poking fun at cringe acting scenes from her early career and emphasising the “shock” she feels at her meteoric rise to success. She even shoos her publicist away when he tells us our time is up, eager to carry on chatting. 

Although Slater has been acting since she was six, the last five years have seen her career take off, landing roles in a DC Comic series, an Indiana Jones film, and a Belgravia spin-off show. Now, she has two horror movies coming out, one of which is called Tarot, premiering on 3 May. It follows a group of friends who unleashed an unspeakable evil trapped within the cursed deck of cards they used during a tarot reading. Hate it when that happens. 

But Slater is most famous for a project she hasn’t even finished filming, Outlander: Blood of My Blood, a prequel to the beloved historical series, Outlander. It will chronicle the love stories of Jamie Fraser and Claire Randall’s parents, the leading couple from the original show. Slater will play Jamie’s mother, Ellen Mackenzie. After eight months of auditioning, she had given up hope but was dumbfounded to hear she landed the role: “It really sunk in that my whole life is changing – and that I was moving to Scotland.”

Hailing from Leicester originally, Slater had been working toward this moment since her very first production in Annie Get Your Gun at the Little Theatre. She was hooked on the adrenaline rush of performing in front of a crowd; it was the first time in her life that she felt empowered. “I think it was like a massive stress relief. I was a very anxious child. It’s funny because in a way it’s terrifying to get on stage in front of hundreds of people. But it fills you with so much confidence, especially when it goes well.”

Slater’s parents went above and beyond to support her acting career, becoming chauffeurs to her theatre and dance rehearsals without so much as a complaint. But the seed for this dream was planted at her grandparents’ house, who were film and theatre obsessed.

They babysat her once a week where she religiously watched The Wizard of Oz on repeat. As members of the Leicester drama society, they nurtured her interest in acting and spent their spare time working on local theatre productions. Now, their names are engraved on the back of the chair in the auditorium while their granddaughter goes on to have hers pinned to a Hollywood dressing room.

Harriet Slater

Square Mile: You have two horror films coming out this year; were you always interested in the genre?

Harriet Slater: I used to find them terrifying. I remember watching Luther with my parents when I was a young teenager and I was traumatised. I’ve never forgotten that one episode where there’s someone hiding under the bed. It scarred me. Even now whenever I come home I have to check all the crevices of the house to make sure there’s no one there.

But when I was at drama school, I got really into them because my boyfriend is a huge horror fan. It’s strange that in one year, I did two horror films. They were both with Sony and both in Serbia. It was bizarre. I don’t want to make a name for myself in any one particular genre. I’d love to just keep working across all of them.

But I wouldn’t say no to another horror film. My favourite horror film is Hereditary – and I also loved Midsommer. 

SM: Was the experience of filming Tarot as terrifying as the movie looks?

HS: The special effects makeup was incredible, and they used real people to play the monsters. In your head, you know it’s not real, but your body doesn’t always know that – especially when you’re running through houses away from these people who are chasing you. The adrenaline was pumping. There were times when I really had to calm myself down and remind myself that it wasn’t real. 

SM: How do you get into character with a role so different to your personality?

HS: With theatre, you get the luxury of having a whole arc in chronological order. You go from start to finish each night. Whereas with screen, most of the time, scenes are completely out of order, story-wise. But that does also mean that you get the time before action is called to get yourself in that state.

But I think the more life experience you have, the more experiences you have to draw on to get into character for a scene. These horror films have especially taught me how to get to that emotional place because I never had to do it to that extent.

You find triggers that work for you. Everyone has their own different ways of doing it. Some people listen to music, and that really helps them get into the state of mind of the character. But I just tend to use my imagination mostly.

Harriet Slater
Harriet Slater

SM: How did you land the Tarot role?

HS: I auditioned for it in April and didn’t hear anything till October. I got a call and they were like:  “We need you to fly out to Serbia on Thursday.” So, I dyed my hair blonde and flew out. It was a complete whirlwind. That’s the crazy thing about this industry. From one week to the next you really have no idea what you’re gonna be doing or where you’re going to be doing it anywhere in the world. 

SM: What was it like filming in Serbia?

HS: There were some incredible locations there that I don’t think we would have been able to shoot the equivalent in America, which is where the movie is actually set. There’s one scene on a huge bridge and they managed to shut it down two nights in a row. 

I spent a lot of time with the girls in the film. When we were on the bridge together, the sky was so clear, you could see all the stars so clearly. I downloaded one of those apps that tells you about which stars are above you. We all got super into that.

There’s also a beautiful cathedral and I often walked up there. The girls got a bit more time to properly explore because I was in more scenes than them, which I was jealous about. I want to go back there one more time just so I can explore the country because it looks beautiful. 

SM: Tarot explores spiritual power, would you consider yourself spiritual?

HS: Yeah, I would. I’m not religious. I never have been and my parents aren’t religious, but they’re definitely spiritual and they raised me to be quite spiritual.

My favourite book is The Alchemist by Paulo Coelho; my mum gave it to me when I was younger. It’s about the power of the universe. When you really want something, all the forces work together to help you achieve it. Learning that at such a young age was really powerful for me.

Harriet Slater

SM: Your character Haley gradually learns that not everything is up to fate. Do you believe in fate?

HS: I definitely believe in things happening for a reason. And if something doesn’t happen for you, then it wasn’t meant for you. Especially in this industry, when there’s a lot of rejection, it makes it easier to not look back and think that wasn’t meant for me.

But I think Haley’s more hardcore, she thinks that her whole future is predetermined and there isn’t anything that she can do to change it. I think she is that way because of the death of her mother in the film, which left her feeling really out of control of her life and anyone else’s lives. That belief that it was written in the stars brings her some comfort.

Throughout the film, she starts to question that and the whole plot is that she has to fight fate and rewrite it in order to save her friends. That gives her agency back and makes her realise that actually she has more power than she thought. 

SM: Have you had a tarot card reading?

HS: No, I haven’t. I had Zoom sessions with this tarot expert called Angie, who they employed on the film to make sure that everything was correct. But I’d love to have it done because I think it’s fascinating. And I think it can be a force for good. I know the film kind of depicts it as an evil thing at times, and I really don’t think it is. It can be a very positive experience too. 

SM: Ever had a paranormal experience?

HS: I used to work behind the bars of West End theatres when I was between jobs. There was one time at the Shaftesbury Theatre when me and another bartender both thought we saw someone behind the bar. We thought it was the other guy that was meant to be working with us. But then like a few minutes later, he came through the door and said: “I just got here.”

I know quite a few people who have some really cool, compelling ghost stories. It’s fascinating, I think there’s so much evidence for them. I actually had a moment when I was shooting [True Haunting]. I suddenly woke up in the middle of the night and thought: “Oh my god, this is a true story. These ghosts that we were making a film about are real. What if they know that we’re doing this film? What if they don’t like it?” I was spiralling!

Horror films have made ghosts a negative thing. If they do exist, there’s no reason to believe that they are malicious. They could just be guardians watching over us. That’s how I like to think about them.

Harriet Slater

SM: What was the most difficult role you have played?

HS: It was difficult, emotionally, acting in the horror films because you spend days in a rough and heightened emotional state which was intense but also kind of cathartic at times. But each role that I’ve played has presented different challenges, especially accent wise. I’ve done a different accent for each job that I’ve done which has been a fun challenge.

I love learning new accents and getting to play in them. The accent on Outlanders: Blood of My Blood scared me the most because I had never done a Scottish accent before. But now it’s one of my favourite things about it. I think it really helps to get into character when you’re doing a very different voice to your own.

You just need to practise it enough so you can get to a point where it just becomes second nature. I got into the habit of listening to Lauren Lyle from Outlander’s podcast. It helps me to listen to that Scottish voice every morning. 

SM: How did it feel to land a role in Outlander: Blood of My Blood?

HS: I went into shock. I totally wasn’t expecting it to happen. It had been the longest audition process of my life. I taped for it in February and got it eight months later. When I got the call from my agent, I had the most underwhelming reaction. She was expecting screams or tears, which is what usually happens when I get a job. I’ve never reacted in that way. 

It wasn’t that I wasn’t excited. It was more that I was so shocked. Over the next few days, it really sunk in that my whole life is changing and I’m moving to Scotland. 

SM: Given Outlander’s following, do you feel a heightened sense of pressure?

HS: There’s definitely a sense of responsibility to live up to these people’s expectations of what they want for this show and these characters. It’s an honour to play Jamie Fraser’s mother because she’s so important to the story and to the fans; I don’t want to let them down.

But they’ve been so supportive from the moment we were all casted. It was overwhelming how supportive they were. I had a quick scroll through some of the comments and the excitement around it all was so welcoming. So that was a really nice and reassuring way to start.

It’s a lovely feeling because the fanbase is already there. We’re not starting from scratch and we know that hopefully people are going to watch it. We’re working with the same team that created that previous show and I feel like we’re in very safe hands.

It feels like a lovely foundation but we’re also able to build our own unique thing.You don’t have to watch Outlander to watch our show because it’s a prequel. Hopefully, it’ll draw in new fans as well. 

Harriet Slater
Harriet Slater

SM: How did you prepare for the role?

HS: I watched the whole Outlander series. I literally just finished it the other day and I had been watching it for over a year; there are a lot of seasons. I watched the whole thing because I wanted to fully immerse myself in that world and get to know these people. We’ve all been looking for little things that we can latch on to that might be nice to include in our show.

I also met a couple members of the cast of Outlander and they’re all lovely. I had a lovely chat with Caitriona Balfe a couple of weeks into shooting. I found that so helpful talking to her because it felt a tiny bit overwhelming at the start. This is a huge job. It’s my biggest show that I’ve ever been a part of. Her one piece of advice was to enjoy every moment. 

It can be so easy to get caught up and scare yourself by looking at the bigger picture. I feel so lucky to be a part of something like this. This is literally the life that I was dreaming of ten years ago. 

SM: What can you tell us about the plot?

HS: All I can say is that it follows the love stories of Jamie’s parents and Claire’s parents, which occur separately. Jamie’s parents are living in 1715 Scottish Highlands and Claire’s parents are living in 1920s post-war England. Their love stories run parallel, but in very different times. 

But playing the character of Ellen MacKenzie is teaching me a lot about myself. It’s fun when you push yourself as an actress to places you’ve never been or didn’t know you had that inside of you.

SM: Many of your roles are period pieces; what is your favourite historical era?

HS: Well, I would love to do something set in the Tudor period. The costumes of that time draw me in; the hair and makeup is just stunning. I don’t know why we don’t dress like that anymore. Although, I’m very glad that we’ve moved on from corsets and ridiculously large skirts that make it impossible to go to the loo. But I find that period fascinating because the stakes are so high all the time. It was literally a matter of life and death a lot of the time.

It’s very Shakespearean because you get to the root of the extremes of emotion. Especially King Henry VIII and the whole story of the monarchy around that time. I’d love to do something set in that period.

SM: How is filming in Scotland?

HS: It’s beautiful. I had a moment where I came out of the toilet on set and was met with the most stunning mountains; it was an otherworldly view. They call the toilet the ‘honey wagon’ here which is such an odd name for not a very nice place.

Anyway, I feel so lucky that we get to go to these places and shoot somewhere with castles. I love castles so much; I’d visit castles on my day off anyway, and now I’m being paid to film in and around them. 

The scenery is mind-blowing sometimes; it’s almost like a character in itself. I think it will probably upstage us in a lot of scenes. Also, the people of Glasgow are just so nice, friendly, and welcoming. I feel at home here very quickly.

Harriet Slater
Harriet Slater

SM: What has been the most defining moment of your professional career so far?

HS: I feel like I’m in the middle of it right now. But getting my first job really set me up because that’s how I got my agent. A director that I worked with in my final year of drama school asked me to audition for a play about cycling called The Man with the Hammer and I got it. That’s how I landed my agent because she came to see it and signed me. It’s all basically a series of meeting people who believe in you.

Another defining moment was when I got cast in Pennyworth because that was my first screen job. Getting that first TV role was a pivotal moment because it’s almost like a different industry to break into.

I gained so much experience and learned what to do on screen and what not to do on the screen. I very much learned on the job because I’d had no previous screen experience whatsoever. 

SM: How did your family react to watching you on screen for the first time?

HS: Well, I can’t bear watching myself. I hardly ever watch myself back if I can avoid it and especially not with anyone else in my presence. Sometimes, it’s important to watch because you can learn from what you’re doing, especially in the early stages.

I’ve watched all of Pennyworth because I wanted to learn what worked and what didn’t. In the early days of my screen acting I would just say to myself: “Why did you do that?” But then you learn from it and do better next time, hopefully. It’s quite common for actors to not like watching themselves. There’s just something terrifying about it. It is so exposing.

The hardest part is listening to the sound of my voice. It never sounds like you think it is, especially when you’re doing an accent. Now, the more that I’ve watched myself, the easier it has gotten. And I actually really enjoyed watching Tarot. So that was a nice feeling. Finally. 

My parents are very supportive. They watch everything I do – and then they let me know whether they liked it or not! And most of the time they like it, thank God. 

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Tarot is in cinemas now.