All Creatures Great and Small star Rachel Shenton reveals Helen's Christmas special wedding dilemma

"There's such a lot going on for Helen. I think her emotions are so complex and I think honestly it might be the first time she's ever really thought about what she wants," Shenton tells press at a Q&A ahead of the Christmas episode.

"Hugh and Helen got together when they were super young, they've kind of grown up together, and then their lives got really serious really quickly. They both lost parents, Hugh inherited the estate, she looked after the farm and her family. So they never really had a romantic courtship or any sort of exploration of their relationship, really. So you cut to a proposal, and I think it's overwhelming."

Since James turned up in Darrowby to work for Siegfried Farnon (Samuel West) as a veterinarian, there has clearly been chemistry between him and Helen. But Helen was already in a relationship with Hugh, and so James held back from telling her how he felt. Then, just when it looked like he was about to reveal his feelings in the series one finale, Helen and Hugh announced their engagement.

Now, in the festive special, it's Christmas Eve – which means it's also the eve of Helen's wedding. According to the episode synopsis, James is trying to "bury his pain" and has invited his new girlfriend Connie to a Christmas party; but when he's called away to assist a distressed dog in labour, and "Helen asks if she can go with him to get away from all the wedding gossip." That turns out to be bad decision when they get trapped overnight by thick fog, but James promises to get Helen home in time for her wedding.

In the episode, Helen must think properly about her future and her decision to marry Hugh. "There's just such a lot going on," says Shenton. "And I think she's forced to really think about that for possibly the first time, because she's a real head-down, crack-on kind of girl."

Asked whether Helen is marrying Hugh to please her family, Shenton says: "I don't know if it's what she thinks her family wants necessarily. I think it's the assumed trajectory of a relationship especially then and when you've been together for such a long time, it's kind of what everyone's expecting. And he's great! They've got a lovely relationship, they get on very well, and he's more than eligible. It makes sense to marry Hugh. But yeah, there's just something, isn't there?"

For his part, Nicholas Ralph describes the Christmas special as a "rollercoaster" with "a lot more ups and downs".

He adds: "There's been this constant battle throughout the series for James, with her in mind. And also the moral dilemma of being a good guy, doing the right thing – but also he has these profound feelings and desires. And certainly at the start, when he meets Helen, we see the profound effect she has on James, and I think it is like: heart beating out of your chest, sweaty palms, stumbling over your words and sentences, not making too much sense.

"But he of course grows in confidence, and as we see a bit more of Helen and Hugh's relationship as well, that all has an effect. I think also James is a very smart, conscientious guy, which makes him very perceptive and perceptible, so we'll see.

"But I think if you asked James where he saw himself in three to five years or where he'd like to see himself professionally and family life or whatever, I think he would be able to tell you instantly, he wouldn't have too many thoughts about what the answer would be."

Of course, in reality 'James Herriot' (Alf Wight) did marry his 'Helen Alderson' (Joan). But the new Channel 5 adaptation hasn't totally followed the books or the BBC original so far, leaving fans on tenterhooks about the future of James and Helen's relationship.

Channel 5 has also released this image ahead of the Christmas special, titled "Wedding Day" – but is that Hugh's hand, or is it James's, or does it belong to someone else entirely?

All Creatures has now been renewed for a second series, so there'll be plenty more space to tell their story – whatever happens.

Speaking ahead of the show's 2020 Christmas special, writer Ben Vanstone says: "I'm a big fan of Christmas TV, I'm one of those people who gets a Radio Times and circles every show I'm looking out for." (We approve.)

"And I suppose from the outset... I wanted this to be a real treat and have warmth, heart, festive stories, the sort of show that you're going to sit and watch with your family drinking sherry – not the children! But I think as well, therein lies the danger with it a little bit too, because as well as having all that warmth and that family glow at Christmas, it can also be a sad time as well.

"So it's making sure that you're striking that tonal balance across the story, so yes it has warmth and heart but it isn't too saccharine. With regards to the stories themselves, I think there's three key moments in his episode towards the end that sort of encapsulate the final endpoint of our characters' arcs – which I can't talk about because I'd give away too much of the story.

"But those sorts of images, as it were; I had those probably four years ago now, five years ago, and it was always going to get to those points, and the Christmas special was what sort of wrapped them all up together."

The All Creatures Great and Small Christmas special will air on 22nd December 2020 at 9pm on Channel 5. You can buy James Herriot's books on Amazon. While you're waiting, take a look at our TV guide to find out what's on this week.