Synnøve Karlsen is a memorable name and one you better get used to hearing. The 25-year-old actress has enjoyed a start to her career so fast it would give our cover star Max Verstappen whiplash, and the speedometer is only heading in one direction. Her first role was the lead in BBC One thriller Clique. Her first feature film is Edgar Wright’s immensely anticipated Last Night in Soho. Based on current career trajectory, expect her to be announced as the next James Bond in two years and Prime Minister of the UK in ten.

And it’s pronounced syn-er-va, in case you’re wondering. Rhymes with Minerva. Her father’s Norwegian, her mother’s American, her accent’s English – although she was born in Glasgow and raised in the Scottish coastal town of Helensburgh. Of her three brothers, one lives in New York, another in Texas and the third in Dubai. Basically, Synnøve Karlsen is cooler than you – as evidenced by her role in Last Night in Soho, the coolest film of the year.

Last Night in Soho is a psychological thriller directed by Edgar Wright (cool) and starring Matt Smith (the coolest Doctor Who, sorry David), Anya Taylor-Joy (made chess cool), the late, great Diana Rigg (Emma Peel, say no more) and Thomasina McKenzie, best known for her role in famously cool director Taika Waititi’s JoJo Rabbit). The setting of 1960s Soho is almost like coolness overload. Although, Karlsen tells me, one of her friends used to live in Soho: the bins are collected daily at 4am and, being 95% composed of empty bottles, apparently the noise is deafening.

Whereas TV shows tend to involve several directors, Last Night in Soho is very much the product of Wright’s vision. “Edgar knows exactly what he wants,” says Karlsen. “You come in every day and he has storyboards on the side. So everyone in the crew can go and look at the storyboards for the upcoming day, so you can see exactly what the plan is. He knows how he’s going to cut, he knows how he wants to tell this story.”

Karlsen plays Jocasta, tormentor of McKenzie’s time-travelling fashion designer. “She’s sort of the main antagonist,” says Karlsen. “She’s not the nicest of people.” Unlike Karlsen herself, who’s great company: sharp, witty, self-deprecating. If you were hitting a night out in Soho, you’d doubtless have a blast with her.

Synnøve Karlsen

Cocktails at the Groucho then? No, Karlsen isn’t the members’-club type. Instead we meet for lunch at Bellanger, a Parisian-style brasserie in Islington where she is a regular. The decor reminds her of the Titanic and I completely understand the comparison, what with the polished oak surfaces and the uniformed waiters and the splendid bar that spans the central dining room. All very beautiful; très belle époque. The kind of place where you feel underdressed without a dinner jacket and cravat, and all the more enjoyable for the sensation. Plus there’s minimal risk of icebergs on Islington Green.

Karlsen doesn’t come from an acting dynasty, nor did she spend her childhood practicing monologues in front of the mirror: only during a school production of Anton Chekhov’s The Seagull did the realisation strike. “Ooh, I’d quite like to give this a go.”

Some go she’s giving it. Acceptance into the prestigious Guildhall School of Music and Drama should have mapped out her next three years, only life had other plans. Karlsen was spotted singing Joni Mitchell at her brother’s wedding. A casting director reached out over Facebook, inviting her to audition for Clique. “And then I got the part. And then I got an agent. And then I started filming about a week later.”

First ever audition? “First ever audition, yeah. It was crazy.”

BBC One show, lead character… “Main part. Every scene.”

Everyone at Guildhall must have both admired and massively envied you. “I was so worried about that! I was so worried about what people would think. Also, trying to get into drama school seems like the be all or end all. It was so competitive. Then I got in, and the idea of leaving, leaving all these friends...”

She describes drama school as an ensemble, almost a theatre company. There are only a small number of students in each year – “like, 24” – and you’re meant to learn and perform and grow together. Leaving after two terms isn’t in the script, although how could she not have done? “I had all this guilt about it. But definitely the right thing to do.”

Synnøve Karlsen

Anyway, Clique served as a surrogate drama school. A campus thriller set in Edinburgh University, Clique combined the glamour of Gossip Girl with the unabashed hedonism of Skins, throwing in some shadowy conspiracy for good measure. Filming was a wonderful experience and a challenging one.

“I literally fell in love with everything about it,” says Karlsen. “It was just a dreamy time. But it was also quite intense. I got really into it. Didn’t really know how to take care of myself particularly well. I just put everything into my work. Didn’t have a laugh. Didn’t really look after myself.”

At an age where most of us were – well, better not say – Karlsen was preparing to anchor a major TV show on Britain’s biggest channel. She pushed herself, and kept pushing. After the first week of shooting, the cast had a day off. Karlsen had no idea how to spend the time. She was miles away from home. She wanted to get back to work.

“When you’re 19 and you’re living in a hotel, that’s not the safe home that you need. It’s very easy to stop taking care of yourself. Not feeding yourself properly, not sleeping properly. Things like that. They’re really fundamental things.” She grins. “That’s why I love living at home!”

She’s currently filming The Midwich Cuckoos, an eight-part Sky One adaptation of John Wyndham’s classic science fiction novel. She plays the daughter of Keeley Hawes, impregnated by a parasitic alien. There are many great things about the project, not least its proximity to North London – allowing for home comforts and visits to Bellanger whenever the chance arises.

Synnøve Karlsen

On the matter of lunch: Karlsen goes for a large salad with bacon and duly demolishes it. I opt for a chicken schnitzel sandwich from Le Brunch menu, which turns out to be more or less a fried chicken burger. A very good fried chicken burger, and it’s not Bellanger’s fault that I visited my local chicken shop the previous evening. (Shoutout to Maeme’s West Norwood, making its first and most probably final appearance in Square Mile.)

My dining companion can empathise. After the premiere of Last Night in Soho, she found herself back in her hotel room, searching Deliveroo for takeaway options. It was late, so late that the only place still serving was Morley’s. So Morley’s it was, a sizable order of fried chicken delivered to her extremely upmarket hotel. This is someone in no danger of losing her head to fame anytime soon.

The end of Clique hit Karlsen hard, though. She compares it to a break-up. Weeks and months spent working with the same people, colleagues who become friends. Then one day it stopped. “Everyone disappears. Everyone vanishes. They all go back to their own lives. And the set’s gone. And the story’s over.

“This is the reality of being an actor. You fall in love with the character or you fall in love with the place that you’re filming or the people you’re filming with. And then it ends. Within three months, it’s over. It’s the most intense thing ever and then it’s over.”

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But as one project wraps, another calls action. After Clique came Renaissance drama Medici – a recurring role as Clarice Orsini that required months filming in Rome with the likes of Sean Bean and Sarah Parish. “That was crazy,” says Karlsen. “That was fun. I did four months of Clique, then four months of Medici, then four months of Clique again, then four months of Medici. That was my first two years.”

Was it strange switching from Edinburgh University to Renaissance Italy? “It was weird. Medici I was playing this medieval, almost virginal character who wants to be a nun; Clique I was out partying and hanging out! They were both fun. Both brilliant jobs, I learnt a lot, I worked with brilliant people.”

She tells me about living in Rome – just as glorious as you’d expect – and then about growing up in Helensburgh. Notable former residents include engineer Henry Bell, pioneer of Europe’s first commercial steamship, and John Logie Baird, the inventor of television. It’s a beautiful place, says Karlsen. “It’s a big place for sailors. Lots of Olympic sailors are from there.”

Drive five minutes up the coast and you’ll find Faslane Peace Camp, occupied by a fluctuating population of pacifists since 1982. Another five minutes and there’s Clyde Naval Base, home of Britain’s nuclear stockpile – despite the Peace Camp’s best efforts. If and when armageddon occurs, Helensburgh will be among the first to know. Perhaps that’s why the town produces so many Olympians: being neighbours with a fleet of nuclear submarines must really concentrate the mind.

Synnøve Karlsen can already be counted as another of Helensburgh’s high achievers – she mightn’t have invented TV, but she’s well on her way to owning it. Many big nights lie ahead. Remember the name. 

Last Night in Soho is out now