WHEN Last Tango In Halifax debuted back in 2012, writer Sally Wainwright couldn't have predicted its success. Inspired by her own family, the comedy-drama follows former childhood sweethearts – now 70-something widowers – Celia and Alan, who have reunited later in life, much to the initial consternation of their respective grown-up daughters.
"This is definitely the most personal thing I've written about," Wainwright said after it aired, the scenario largely based on her own mother, who had reconnected with and married a former flame some 60 years later.
Praised for its depiction of the older generation, stellar casting and relatable dialogue – not to mention the idyllic Yorkshire scenery – the surprise hit went on to scoop a Bafta for best drama series after just one season.
So preparing for its fifth chapter all these years later is quite an achievement.
"When you write the first, you never know if you're going to get a second," muses Wainwright, at the glitzy series launch.
"But it's a self-generating thing in many ways. The characters, well the actors, have brought them to life so beautifully, so it does feel like it could go on."
The actors in question are series leads Anne Reid, Derek Jacobi, Nicola Walker and Sarah Lancashire, who, among others, will return for its latest four-part run on BBC One.
So what can we expect? Now seven years into their marriage, Alan (Jacobi) and Celia (Reid), having moved into a desirable bungalow with stunning views across the Calder Valley, aren't quite seeing eye to eye. Their differing politics and a new supermarket job for Alan are both a source of tension.
Meanwhile Caroline (Lancashire) finds herself entangled in an emotional debacle with someone at work, and Gillian (Walker) faces trouble with a giraffe (yes, really!) at Far Slack Farm.
Along with some new faces, fans can also expect to see the return of Alan's brother Ted (played by the brilliant Timothy West), who arrives on a one-way ticket from his holiday in New Zealand.
For Wainwright, it was a dinner with co-stars Lancashire and Walker that spurred her on to end what had been a three-year hiatus.
"It was just hilarious. I was just sitting there listening to the two of them, and I was thinking, 'I've got to write something for them'," she recalls, the last series having aired in 2016.
"And I'm in the stride of it now – I write for these four extraordinary performances, so it's a joy, it's therapy," she shares.
"Whereas writing other things, like Gentleman Jack, is really hard because I'm working from a diary, so it's very intense.
"This is just the opposite, I can do what I want!"
"Well I've been desperate to get back!" cries Reid (84).
"I kept being rude to you [Sally], didn't I, publicly? And saying, 'She just won't write any more', and so Sally said, 'You've got to stop saying this!' But I'm thrilled, we all are."
Who wouldn't be, given the chance to play Celia – warts and all?
"She's a right grumpy bugger!" quips the former Corrie actress.
"But I say to Sally, 'Please don't ever make her nice', because I love it. If she turned terribly sweet, I wouldn't like that. You get more laughs if you're unpleasant."
As for berating Alan for getting a job: "Oh darling, he has to wear a uniform and stand behind a till – and she's a terrible snob," Reid empathises.
"She has delusions of grandeur, she wants a husband who works in an office and looks nice and doesn't wear a uniform. She wants him turned out nicely."
She follows: "In the beginning, she always had the upper hand. Yet after seven years, he's not quite so besotted with her. I know she's difficult, but I really think he holds the whip now."
"He's on the turn, yes," Jacobi (81) agrees.
"I think I need a little bit of my independence. I can see flaws in her that I didn't see before, and I can make my opinion known at last.
"It is an effort, I'm on thin ice with her all the time, but I'm determined to state my case and be my own man," he notes.
"And getting a job, getting out, meeting other people, helps."
Gillian, on the other hand, has her own issues: woodworm.
"It's a very serious issue. I have borrowed an extremely large amount of money to expand my flock [of sheep]" Walker (49) confirms.
"I'm actually happier than I've ever been as Gillian – but it's life, isn't it?
"The woodworm comes along and it's just an extra debt that puts the water over her head – and she needs her dad," she maintains.
"I've still got my son living with me, with his partner and his child, and I'm still relying on my dad – it's very familiar."
It's fair to say Caroline struggles to cope this series at times, too.
"She's pretty much a constant," says Lancashire (55).
"I think further down the line we do see an element of her not coping particularly well, which is unusual for her.
"Basically she's got too many plates to juggle and she's not sure she can do it, but also she's dipping her toe again in the water, in terms of a possible relationship with a colleague," teases the Happy Valley star.
"We haven't seen them [Gillian and Caroline] for a while but it is really clear that they're very close now," interjects Walker, who is also currently starring in The Split.
"They've become like stepsisters, haven't they?"
"Yeah, they know things about each other that nobody else knows, and so that relationship has matured now," Lancashire adds.
So five series in, with a worldwide fan base. Why is the show so loved?
"It's filled with comedy and drama, and [viewers] just seem to have taken to the family," Reid says simply.
"We knew it was good, but we didn't know it was going to go so universal – America, in New York and Tasmania," she says.
"It's kind of weird and wonderful when people run after you in the street in Port Hobart shouting 'Hey, it's Celia!' But it's lovely.
"It's always the script, basically, it really is," she finishes.
"I mean, you can't do anything with a bad script, so we owe Sally a great deal."
:: Last Tango in Halifax, BBC One, Sunday nights
