Sarah Lancashire is sitting at the table in a set resembling the interior of a cottage.
Camera operators and lighting technicians bark orders at one another, while a woman from wardrobe constantly fiddles with the collar of Lancashire's shirt. Amid all this hustle and bustle, the actress remains absolutely still, her head lowered.
Finally a hush descends. "Action" is yelled, and a moving scene between Lancashire and her co-star Nicola Walker plays out for the umpteenth time. As soon as "That's a wrap!" is called, the previously morose-looking actress lifts her head and grins.
"Sorry if I was being a bit actory then, it just helps me to be quiet," she says.
The scene marks the end of the shoot for Lancashire, who for the last few months has been filming the much-anticipated second series of Last Tango In Halifax.
"The schedule's demanding but it's not a hardship, because it's so stimulating, and as an actor you wait an entire career to be involved in a project like this," says the Lancashire-born star.
The romantic drama follows former childhood sweethearts Alan and Celia, played by Sir Derek Jacobi and Anne Reid, as they embark on a relationship after reuniting in their seventies – as well as the troubled goings on of Celia's daughter Caroline (Lancashire) and Alan's daughter Gillian (Walker).
It would be easy to underestimate the series, given its gentle-sounding premise, but it's as dark as it is comic and proved a huge hit with critics and viewers when it was shown late last year.
"People have absolutely taken it to heart and love the fact that it's a romance essentially about older people, which is something we've shamefully had to wait a very long time for," says Lancashire, 49.
"It doesn't surprise me because we can all relate to a multi-generational family."
She stresses that its success starts and ends with the Bafta-nominated television writer and playwright Sally Wainwright, saying: "We're very blessed to be involved with one of her projects."
But, just as musicians can feel trepidation ahead of a second album release, the actress wonders what the reaction will be to this follow-up.
"I suppose people have expectations of what they think the series is now, and invariably you hope you're not going to disappoint, but I don't think people will be disappointed. It's absolutely terrific stuff.
"We're a real company of actors and we more than get on, we care for each other," she says, adding that she relished every moment playing the depressed, Oxbridge-educated Caroline, a role that earned her a Bafta nomination earlier this year.
In the first series, viewers witnessed the headmistress attempt to cope with her adulterous husband, as well as the repercussions of her own affair with Kate, a female colleague.
"The nature of the role I play has clearly hit a nerve with a lot of people," she says. "They haven't seen that nature of a relationship portrayed or written in such a sensitive manner. It's not there to shock, it was really beautifully done."
As the series isn't filmed chronologically, Lancashire wasn't aware her character was gay until half-way through the production.
"The director phoned me and said, 'I think you ought to know this'," she says. Was it a shock?
"Yes, it was a huge shock," she laughs, though it didn't change how she approached the role.
"I approach it as a human being, that's all. I don't look at her gender or sexuality," says Lancashire, who has a ten-year-old son with second husband, TV producer Peter Salmon, and two grown-up children from her first marriage."
She notes that some of the scenes between Caroline and Kate are "absolutely heartbreaking".
"I can entirely relate to that, because it's about human emotion. Love is love," she says. "It doesn't matter about sexuality, but about how you feel towards somebody else, and being kind and good and honest with them."
That said, Caroline "isn't out and proud". Lancashire explains: "All the way through the second series, it's very much a clandestine relationship in that she hasn't quite found the courage to just step out of the closet and go, 'Here I am, and this is me'."
It's left to Kate to try and help her find the confidence. "It's interesting. You think Caroline has the upper hand in most things, because she has that arrogance but, interestingly, a lot of guidance comes from Kate."
Last Tango marks a departure for the actress, whose most recent projects have been period dramas (Lark Rise To Candleford, The Paradise and Upstairs Downstairs).
"The lovely thing about Last Tango is that you don't have to hold back. You can bare your entire soul because it's a contemporary piece, and Sally gives you a lot to work with," she says.