Poldark's Heida Reed: Ross's fans won't like Elizabeth this series

She’s half-joking – but since taking on the role of Ross Poldark’s childhood sweetheart, who married his cousin Francis while he was off fighting in the American War of Independence, she has had to dodge the grapeshot fired by ’Darkers, the name given to Ross’s more devoted digitally active fans. “It ebbs and flows, I guess,” she shrugs. “I said to my manager one time, ‘I want to be an actress in the 90s, before broadband.’ And he’s like, ‘Well, tough. You’re not.’”

Haven’t people gradually warmed to Elizabeth as she battled with being a single mum and made a less-than-loving marriage to feed her son? She shakes her head. “If people felt bad about me before, I predict they’re going to feel even worse about me this season,” she laughs. In episode one of the new series she spurns Ross when he attempts to help her and gives birth to a child that, thanks to the controversial rape scene in series two, could be Ross’s.

Whose baby is it? “I don’t think Elizabeth has a very clear feeling about the paternity of her child, because it’s so terrifying to her that it might not be George’s,” she explains. “If it isn’t and it gets found out, she is in so much trouble. I mean, her life is over. So she struggles to connect with the baby and a governess arrives to look after Geoffrey Charles [the son she had with her first husband, Francis], the one real, true, pure connection that she has. She fades, she gets colder, loses patience and loses empathy. So I really don’t see Ross’s fans warming up to her, but I hope that, once she’s gone through her journey, they see the beautiful sadness in her life."

As Elizabeth she’s cut-glass and cold – and watching her close down still further in series three, she becomes the epitome of an unhappy, class-ridden Englishwoman. It’s so uncanny that it’s easy to forget Reed, 29, is Icelandic, growing up on the outskirts of Reykjavik with a pianist father and dental hygienist mother.

“We don’t have the class system in Iceland – we’re just one class and then some people are rich, but they don’t consider themselves a part of a different class,” she explains. “You don’t realise how important it is until you’ve been here for a while. Playing Elizabeth I have started to develop a slight resentment towards the upper classes – because, if this class system existed in Iceland, I probably would have been working class.”

Whatever class she may be, she’s been working since an early age. She went to ballet school and was always putting on shows with friends. Then she was scouted, aged 15, by a modelling agency while she was out shopping. At 18, she moved to India – spending two years appearing in TV ads and beauty campaigns where her fair skin, dark hair and green eyes went down a storm. Aged 20, she pitched up in London, changed her surname to Reed (from Sigurdardottir) and won a place at the Drama Centre.

“I wanted to act on an international level, so I was choosing between London and New York,” she explains. “Most people said that there was better training in London. And also then, you know, it made sense financially being able to work here – ironically, because Britain was part of the EU. Now I don’t even know what the rules will be for me – I feel like I’m in limbo.”

Partly as a result of this, and partly because it’s where her boyfriend, producer and actor Sam Ritzenberg, lives, she’s in the process of moving to Los Angeles – albeit slowly. “LA is a strange town when you’re in this industry – you require a level of cynicism just to function there,” she says earnestly. “If you’re just too open and honest and gullible, then you’ll probably go down painfully at some point. But I love California. It’s beautiful. So that’s where I’m aiming to end up by next year. I’ve moved half my stuff, but I have so much to do in Europe I’m just tentatively putting it [the move] on hold for now.”

That European stuff includes Icelandic TV drama Stella Blomkvist – about a sultry police detective who is “like Sam Spade, with a law degree and sexuality” – which she’s currently filming on night shoots. She raises her mug of coffee: “This is my fifth cup today,” she grins. “I have a crazy tolerance lately. Two months ago I would have had one. Now it’s unlimited.”

Then there’s series four of Poldark to shoot – which she’s looking forward to, because she misses her cast mates Aidan Turner and Eleanor Tomlinson (who play Ross and Demelza). When they’re all in London, they go to the pub or have dinner together – she likes to cook for them when she’s not wearing Elizabeth’s corset, which is “so tight I can only eat soup and smoothies”. She particularly loved last year’s Baftas, where the show won the Radio Times Audience Award, voted for by the public. “So please thank your readers for me… winning was a huge celebration for us.”

When, eventually, she ends up in LA, she says with the air of someone in a confessional that she wants to move into comedy. “I know that people don’t see me that way so I’d need to write it myself,” she explains. “The people who are like my gods are Judd Apatow and Tina Fey and I really look up to Lena Dunham, Michaela Coel and Phoebe Waller-Bridge – these are the women that are moulding our society today… That’s what I aspire to. Something relevant and important, but also ridiculously funny.”

She’s working on something with someone in LA – that’s as specific as she’ll get – with improvised comedy at the heart of it. Her drive and ambition come partly from her family. Her brother is a stage producer in Denmark and her sister is a dancer, but it also, she says, “has something to do with being from a very small, cold place, where you need drive, creativity and other people to make you feel warm inside. So I think it’s something to do with my nature.”

But before any of that, “I just need to sleep,” she sighs, so tired she’s almost melting through the table, though her green eyes still sparkle. “I want to sleep and eat and hike in California – just walking in the sun, realising how good it is to be a modern woman and not a poor girl whose future is always being decided by men.”

Have you listened to our Poldark podcast yet? Click play below for details of episode three...

Poldark season three airs on Sundays, 9/8c, PBS Masterpiece