All Creatures Great and Small Series 3 stars Nicholas Ralph and Rachel Shenton on James and Helen's wedding and their favourite Yorkshire Dales locations

“I have been told, I am not allowed to reveal,” Nicholas says. “There are new dogs, new cats and, of course, plenty of new farm animals as well. And many returning favourites – Derek, who plays Tricki Woo.”

It is no secret, however, that their characters, James Herriot and Helen Alderson, will tie the knot and that series three will see the couple negotiating their newly married life within the walls of Skeldale House.

“It kicks off with such a lovely, joyful, funny episode. When I read it, I was smiling like a Cheshire cat,” adds Nicholas. “Not only is it romantic, and touching in moments, and thrilling as well – there’s drama to it – but it’s also very funny. A brilliant way to kick off the series.”

But with WWII on the horizon, inevitably, there are darker moments to come for all Darrowby residents in series three, and new responsibilities. James becomes a partner in the practice and pushes to carry out TB testing, a controversial issue within the farming community in the late 1930s.

Rachel says: “The stakes feel more real at times but at the same time, it still has those lovely, joyful moments and lots of laughter and joy.” Nicholas adds: “You will see the characters pushed and pulled and stretched in different ways in this series, which I think is very interesting.”

Rachel nods. “Twists and turns,” she says. “You are definitely in for a ride.”

Filming finished just two months ago, and both are now back in London, but the Yorkshire Dales is now a home from home. “You get to hang out with lovely people again in a beautiful part of the world and read these brilliant scripts – it’s such a privilege to go back,” says Rachel.

Nicholas adds: “It does feel like a homecoming when you come back and see the cast again, and we go out for a family dinner. With a lot of the crew, they live all over Yorkshire and are on different jobs, so we don’t see a lot of them until we are back up to film the next series.”

The real-life modern-day residents of the Dales, especially Grassington (which is used for Darrowby’s exterior filming) were delighted to welcome them back, and no doubt will be delighted again to see them when filming for series four begins next spring. Arncliffe is used for filming the back of Skeldale House.

Nicholas says: “I love Arncliffe, and Malham is right up there now, as well. We were working on this hill, a hill like this [he raises his arm to mimic a steep angle], that has a farm on it. It’s absolutely stunning. You’ve got Malham Scar behind, and people walking. It’s a place that you could film 360 degrees.”

Rachel says: “I like Yockenthwaite, controversially, because when we film there, it has its own eco-system. And also the signal’s not great, you feel a bit cut off, which is not ideal for crew, but I like it.”

Word soon gets out about the exact locations of filming, and ever-increasing crowds of fans flock to watch. “Everybody is so lovely and supportive,” Rachel says. Nicholas adds: “You’ve just got to make sure you’re up to no nonsense because there is always a camera on you.”

But this can mean that it is difficult, if not impossible, to keep a lid on leaks, and pictures of Helen’s wedding dress were taken by members of the public during filming and circulated on social media.

“I guess it’s just the world we live in,” Rachel says. “We filmed outside of the church and you can’t get cover, and it happens. We were just thankful that you couldn’t see too much of the dress.”

And there are still plenty of surprises in store, not least regarding the wedding. “There are lots of twists and turns and it’s funny,” adds Rachel. “You are looking for truth, and in truth there is always a bit of everything. You are looking for as much colour as you can get and, luckily, you are never left wanting with those scripts – they are always so jampacked full of that, and it’s a privilege to read them.”

Based on the bestselling books by real-life vet Alf Wight, All Creatures Great and Small made a critically acclaimed debut on Channel 5 in 2020, with the first series consolidating at 4.7 million viewers.

Beginning in spring 1939, as James and Helen prepare to walk down the aisle, series three will see James feeling torn between his personal and professional life after Siegfried – tactful as ever – reminds him of his responsibilities just as he is getting ready to set off for his honeymoon.

Helen, meanwhile, will face the challenges of letting go of her old life on her family farm with her father (Tony Pitts) and sister Jenny (Imogen Clawson) as she tries to find her new place within Skeldale House. The trailer suggests romance blossoms despite the cramped conditions of the attic bedroom.

In other storylines, Tristan (Callum Woodhouse) is now a qualified vet but is still seeking to win Siegfried’s approval, and Mrs Hall (Anna Madeley) may be ready for love, while Mrs Pumphrey (Patricia Hodge) returns with her pampered Pekingese Tricki Woo (a most welcome reprise for canine actor Derek).

There will be darker storytlines for Siegfried, played by Samuel West, who has to contend with painful memories of his own experiences during the First World War.

The costumes, created by Ros Little, are an essential ingredient of the All Creatures mix, and both Helen and James have new wardrobe pieces. “Obviously, the wedding dress – Ros and the team made that, which is so lovely, but I have quite a few new outfits this season,” says Rachel, clearly pleased. “They are always vintage pieces, authentic, so there is always a little hole that has been darned in a slightly different material, which really adds to it.”

Nicholas says James has “not as much as Helen”, adding: “But I have got a lovely suit for the wedding and a new blazer and some new tank tops.”

They are not allowed to talk about the Christmas episode. “But it is uber-Christmassy and there was definitely a snow cannon or two during the filming of it,” says Nicholas.

He has a role in new film launching on October 28, a Lionsgate horror thriller called Prey for the Devil, and is enjoying reading the third and the fourth instalment of the All Creatures audio books. “It’s really fun,” he says. “I get to play Helen and Mrs Pumphrey and you’ve got 40 different ways to do a Yorkshire farmer.”

Both feel very fortunate to be returning next year to make a fourth series. “It’s an absolute privilege,” says Rachel.

“Likewise,” says Nicholas. “It will feel like five minutes and we’ll be there again. Looking forward to it, and maybe we’ll do a feature film.

“Relationships are so strong and so intricate because the source material is so good, because they are based on real people. James is so multi-faceted that, for an actor, it is brilliant scope. Every day you go in, you don’t know what you are going to be doing – is it going to be funny, is it going to be dramatic? - so there is great variety there, and that’s all adapted superbly by Ben Vanstone, our lead writer, and team.”

Rachel says: “Ultimately, these are stories about community and love, and a group of people who care very much about each other and about their animals, but also about their corner of the world, and I think that feels really relevant and important at the moment.”

Watch All Creatures Great and Small on Channel 5 on Thursdays at 9pm. Also streamed on My5.