All Creatures star teases "huge", emotional storyline for Mrs Hall

"I say it every season because she always just seems to, but I was a big fan of Mrs Hall and Gerald (Will Thorp, it was very hard for me to let go of that [romance]. And then this year, Mrs Hall faces something huge that really sort of tests her mental [health]."

Shenton went on to praise actor Anna Madeley for her performance, adding: "I’m really looking forward to everyone seeing that. It runs for a while, and it's good."

And Mrs Hall isn't the only person whose mental well-being takes a knock in season 5.

Tristan (Callum Woodhouse), who is set to return in a later episode following his time serving in the Royal Army Veterinary Corps, has "obviously changed", according to Samuel West (Siegfried).

"He's obviously seen some horrible things, which he's not talking about," said the actor. "And he's obviously masking with drink and good humour."

But as ever, there will be some lovely, light-hearted moments, such as the relationship between Tristan and Carmody, to counterbalance those weightier narrative strands.

"It's a really fun thing to watch play out, the dynamic between them," said James Anthony-Rose. "Tristan coming home and being met by this curious character, Richard Carmody.

"They’re like polar opposites in one sense, because Tristan is very good at putting a lot of energy into relaxing, whereas Carmody, I describe him as sort of like a precision tool. He puts a lot of energy into his work, and then probably relaxes by doing a little bit more hard work – whether that’s studying for these exams, or whatever it might be."

He added: "So yes, they’re positive and negative in that sense, but through a mission that they find themselves on, they are able to look past their differences."

Read more:

• All Creatures star rejects criticism story is "boring": "It’s the opposite"
• All Creatures stars on Tristan's welcome return: 'He means so much to so many people'

Season 5 of All Creatures Great and Small picks up in the spring of 1941.

Following his work looking after animals in Egypt, Tristan will be "training new recruits who are going to be getting sent out to similar places that he's been in".

And James, who was undergoing pilot training at RAF Abingdon, has since returned to Darrowby after being ruled unfit to fly due to contracting brucellosis, a bacterial disease, through his veterinary work.

Elsewhere, Helen is considering her "contribution within the community" as World War II ramps up while also being kept busy by baby Jimmy, Siegfried is doing his best to keep the surgery ticking along, Mrs Hall has become a blackout warden, and "Carmody is eager to step up".

All Creatures Great and Small season 5 airs on Thursdays on Channel 5 and My5. You can order James Herriot's All Creatures Great and Small from Amazon.

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