Poldark series 3 finale: Eleanor Tomlinson reveals the truth behind the Poldark marriage

He’s written her poems, surreptitiously drawn her lovely image and told her, “I am wholly disorientated… shipwrecked… lost… You are the woman who I love more than life.” But the sight in Hugh’s melting cow eyes is failing after his brutal confinement in a squalid French prison and, to paraphrase inelegantly, he asks Demelza for a quickie before he goes blind. Or, as he puts it, “Shall we grant ourselves each other so I can go into the darkness knowing I have once tasted heaven?”

It’s not a bad chat-up line, agrees Eleanor Tomlinson, who plays Demelza, a woman caught between two lovers.

“Yeah, right,” she laughs. “It’s very funny, but very sweet. I think Demelza just feels honoured by the attention – no one has ever written her poetry before, and Ross has never sat down with a sketchbook and taken the time to draw her. Demelza is swept away by it all.”

It’s the latest talking point between the Cornwall-based drama’s legions of fans – five million tune in every week. Will Demelza, surely the most faithful of women (and she’s had a lot to put up with), cheat on her buccaneering, often inconsiderate husband?

It would be unfair to anyone who hasn’t read Winston Graham’s books and who doesn’t know the outcome to this beach-based tryst to be specific about what happens between Hugh and Demelza.

But the flirtation, which began when Ross (Aidan Turner) rescued his friend Dr Dwight Enys and Hugh Armitage, scion of Cornwall gentry, during that daring raid on the French prison, has intensified on both sides during the third series’ later episodes.

It marks, too, a highly significant moment in the development of Demelza, arguably the character who has come the furthest – emotionally, intellectually and sexually – since Poldark, a hugely successful reboot of the 1970s classic, began two years ago. In the very first episode she was pulled literally from the gutter by Ross Poldark, who thought she was a boy, when she was being abused and teased by a group of yobs in the street.

He took her home to Nampara to be his maid, rescuing her from a brutal father, and not too much later, Ross, enthralled and entranced by Demelza’s spirit, married her.

In many ways it’s a very modern, 21st-century relationship of equals, particularly in this series as Demelza, left to her own devices by a husband who leads a dangerous foray into Revolutionary France, grows and flourishes; she takes charge of the family business, the copper mine, and keeps the home fires burning. Tomlinson has to chop a lot of logs and do a lot of baking and thump a lot of dough: “Ah yes, the angry baking!”

For Poldark’s thrilled and devoted audience it’s been a joy to watch Demelza thrive throughout three series, learning to use her extraordinary power to charm men, secure funds for a community charity project for the starving poor and help her husband as he locks antlers with the wealthy stalwarts of a Cornish society that is on the brink of exploding into class warfare.

“Demelza is not a stay-at-home wilting flower, she is strong and she will go out there and do what she thinks is right for the community,” says Tomlinson, 25, who grew up in Beverley in Yorkshire. “In her independence from Ross she has grown up; she knows what’s right and wrong and how she wants to live her life, and it gives her confidence.”

Demelza has always been forthright, but increasingly demands a bigger voice in the marriage. “Not once have you asked my advice or harkened to my opinion!” she yells at Ross, after rounding on him about the latest manly adventure from which she is excluded.

Says Tomlinson: “Demelza loves Ross, but she doesn’t need him to the extent that she once did and I think that this relationship with Hugh comes out of someone paying her attention, someone highlighting her worth, while she’s being ignored by Ross.

“She wears her heart on her sleeve and she is very true and very honest to Ross and I think it’s lovely. That’s what’s nice about her, she doesn’t conform to a society where women behaved themselves and were very much under their husbands’ thumbs. Demelza speaks her mind.”

But poor Demelza must always and forever fight Ross’s residual love for his former fiancée, the glacially lovely Elizabeth. So is Demelza simply getting her own back with Hugh?

“I don’t think it’s tit for tat at all,” says Tomlinson. “At the end of series two Ross and Demelza decided they still loved each other and marriages aren’t easy, they come with enormous problems, but they decide they have to work through them together and Ross promises to include her in every decision.”

Debbie Horsfield, Aidan Turner and Alison Graham at the BFI Radio Times Festival

Writer Debbie Horsfield, who has adapted Graham’s novels for the screen and has almost completed series four, agrees. “I don’t think it’s motivated by a desire for revenge, that’s not who Demelza is.”

Demelza could probably be forgiven for wanting to get back at the man who has, in all likelihood, fathered a child (Valentine) with Elizabeth, whom he arguably raped in the previous series – and whom he’s now been spotted kissing in the local church. The audience knows that there was a certain let’s-go-our-separate-ways quality to this secret snog, but Ross, for some reason, can’t tell his wife this.

So when the divinely sensitive Hugh peers at Demelza through those prettily fogging eyes and tells her she’s “the woman I love more than life”, surely it’s game on? Not quite, says Horsfield.

“If only Ross had told Demelza what he truly felt about Elizabeth [something only we, the audience, got to hear] at the end of the last episode… It’s important that we know what he was thinking – he’s not just a b*****d. It’s not Demelza thinking she’ll get her own back, it’s more, ‘OK, I really fancy this guy, why shouldn’t I?’

“Besides, it’s almost like they are two kids together, and Ross is caught up in other things so he takes his eye off the ball and is maybe a little too sure that Demelza is not going to be interested elsewhere.”

Indeed, as Demelza wrestles with her conscience and longing and her loyalty to her marriage and two small children, she tells her husband: “I wish I could be two people but just for a day, to give myself to him without it being a threat to our marriage.” And there it is, the key to everything, the Ross and Demelza marriage.

Says Debbie Horsfield: “It’s a genuine marriage, it’s not rose-tinted. In the first series it was lovely, they were falling in love and it was incredibly passionate and really romantic. Then it had its trial and tribulations in series two.

“By series three they were grappling with the challenges of what is going to be a long-haul marriage… What we are exploring is a threat to that marriage that comes from a different place – it comes unexpectedly from Demelza.”

Series four promises plenty of London-based action as Ross moves to the capital to become an MP, which will eventually lead Demelza into even more socially exalted circles.

But initially, says Eleanor Tomlinson, “Demelza becomes more independent, because Ross goes off to London and she very much becomes the boss of Nampara. That is her power – she and Ross are on an equal level and I wonder how he will respond to that.”