Episode three is centred entirely around a conversation between the teenager and the clinical psychologist assigned to his case, played by Erin Doherty. It felt like a potentially groundbreaking piece of television, and taking part was a no-brainer, says the actress, who first heard about the series while working with Graham on boxing drama A Thousand Blows. “He started talking to me about this script that he was collaborating on with Jack Thorne, and I knew that they wanted it to be a one-shot thing, like Boiling Point,” recalls Doherty. “I'd seen Boiling Point, and I absolutely adored it, so I was just like: ‘I can't wait to watch that’. Then we wrapped that job, and I got a call from him a couple of months later that he wanted me to be a part of it.” Graham chose wisely. Building on her strong roles in A Thousand Blows and as Princess Anne in The Crown, Doherty is terrific as Briony Ariston, the clinical psychologist assigned to assess the teenager. Because each series episode is shot in a single continuous take, the entire episode is filmed non-stop. It was an approach that fascinated and initially daunted Doherty - until she leaned into her theatrical roots. “Basically, we rehearsed for longer than we shot, in order to really get it right and to know that when it came to filming, we were on form and ready to go,” she recalls. “The whole thing revolves around the mechanics of making this work. It’s really daunting at first - but essentially, it’s like choreographing a dance. Phil Barantini, our director, was constantly bringing it back to us all being on the same page, so that if anything did fluctuate from the path that we'd like to tread, we were all ready to move as one creative mind to pick up that off-beat. “Once you did feel that level of support, just knowing that when they call ‘action’, whatever happens, we're all going to go with it, I ended up having one of the most fulfilling and joyous experiences that I've ever had shooting a project. “I think also, because I've got a background in theatre, I could click into that mentality of going: when you step on the roller coaster, you can't get off, and you just have to go with it. It's the same thing as going on stage every night and going: what happens, happens. This is the show that you're going to get tonight, and it's its own special little thing. “We shot it twice a day, one in the morning, then we had lunch, and then we'd shoot it in the afternoon, and then we'd go home, because it was just too exhausting, physically and mentally, to maintain that level of focus for any longer than we had with those two takes.” Filming in real time also gave her an extra layer of respect for the therapists and clinical psychologists who do this job day in, day out, she adds. “I can't fathom how they have that mental strength and agility to keep going, because spending three weeks on this project, I was in absolute bits by the end.” An actor who says preparation is her favourite part of her job, she also reached out to her own former therapist as part of her research for the role. She wanted to understand the day-to-day work and the role involved. “I just wanted to really understand what it meant to be in that frame of mind. Then you dive into the actual point, the actual context of what it means to be in that room talking to the character of Jamie.” Doherty is proud of her Irish heritage, and is planning a big road trip to her grandfather’s homeland in the near future. She has also been a visitor to Waterford, where her girlfriend comes from. “My dad's dad, my granddad, was from Carndonagh in Donegal. That's where we're from, and I've always been so proud to have that heritage. Me and my sister would go to him and my grandma every Wednesday after school. He was the kindest, warmest man. He'd always give us a couple of quid to go to the shop and get a little treat after school. We're planning our trip at the minute, me, my dad and my sister. “My girlfriend is Irish as well. She's from Waterford, so she was basically going: ‘We’re going to rent a van and we're going to drive you up there, and we're going all the way down the coast’. We're planning it to specific detail, and I'm really excited that I get to do that with them.” Acting is not Doherty’s only skill - as a teenager, she got scouted to play for Chelsea, and she still adores the beautiful game. Last year, she was thrilled to play at Stamford Bridge as part of charity fundraiser Soccer Aid. “I fell in love with football, so it was very much part of my life. But for whatever reason, the football matches and the drama club that I went to on the weekends both fell on a Sunday, so my dad was having to, bless him, get me in the car in the mornings on a Sunday, drive me to these matches, and then get me in the car again and drive me to the drama club. It hit a point when he was like: ‘I just can't do it’. Some of these matches were at the opposite ends of the country’. “I think acting's always been some therapeutic way of expressing myself and it probably took me about five minutes to understand that I'll just really lean into acting. I could never imagine myself not engaging with this way of being. It's a part of who I am.” Yet her love for football has contributed to her acting career, she feels. “I think what it's really given me is a love of being a part of a team - I think I did get that from playing sport. It's formed that mentality in a way, and I'm grateful for it, because I'm happy to be a small part of something that hopefully reaches people.” Adolescence is now on Netflix