An emotional phone call with a very pregnant Helen makes James determined to get back to her, but he doesn't have many options, and RAF mascot Georgie needs his help. Meanwhile, Mrs Hall prepares a community Christmas celebration in Darrowby, while Siegfried and Carmody argue over who will be Father Christmas.

Just over 50 years ago, an unassuming vet called Alf Wight, under the name James Herriot, put pen to paper and created the global phenomenon All Creatures Great and Small. With access to the film set and studios, Peter Wright and Shona Searson from The Yorkshire Vet experience 1940s Darrowby at Christmas, and get an unseen glimpse into the magic that the Christmas special has to offer.

In the final episode of the series, Helen feels redundant at Skeldale and a million miles from home. When Richard Alderson seems to need help, she returns to Heston Grange. Buried family secrets threaten to tear their relationship apart as Richard refuses to let her muck in on the farm. Helen notices that calf Smokey seems unwell and tries to help him, but it only makes things worse with her dad.

Mrs Hall is blindsided by Helen's plans and worries for Siegfried, but knows she must follow through on her decision, however painful it may be for everyone. Meanwhile, although Gerald's beloved dog, Rock, needs veterinary help, he is too worried about the operation. Mrs Hall pushes him to do the right thing.

And Mrs Hall must make her final choice and let go of something special. Both Mrs Hall and Helen are about to learn where they truly belong.

The War is getting closer, James is about to embark on a new journey. He desperately wants things in order and Carmody trained up to support Siegfried. But James is frustrated at Carmody's inability to drive and he keeps missing opportunities to spend precious time with Helen. His grand plans are derailed when an injured cat is brought into the practice. The vets have little hope for the cat, but he might be just what they all need.

Carmody and Pumphrey clash as he can't see her dogs the way she does. An unexpected offer might bring the two together and get Carmody ready to step into new responsibilities.

A dinner with Gerald leaves Mrs Hall with a dilemma but watching James and Helen brace for their future gives her a new perspective on her own.

James and Helen are keeping a secret. Following a visit to the Crabtree's Farm, Carmody is challenged with learning how to be a vet outside of his books. The new farmers have a worrying illness amongst their herd and James wants to help them in any way he can. Helen volunteers to join him, but helping the Crabtrees might have had a bigger impact on James and Helen than they anticipated. Helen rallies the community to help the newcomers while she waits for some personal news.

Carmody meets Bernard the tortoise and tries to ‘treat the owner' too by helping Ned Clough. Despite confiscating his textbooks, the whole household will come to realise the value of Carmody's bookish ways.

Mrs Hall receives an important letter and has to decide whether or not to share the news.

Busy and exhausted from lambing, James and Helen can't get any time together. James thinks he's found a solution as he's hired a new trainee vet, Richard Carmody, but things don't quite work out as he expects.

Mrs Pumphrey also has a new canine member of her household, Cedric, who has an antisocial problem that she needs addressed urgently. Tensions come to a head at Mrs Pumphrey's Community Tea Party, and Mrs Hall takes a big step forward in her relationship with Gerald.

Beloved horse, Teasel, needs expert help from the Skeldale House vets and Helen realises that life happens while you're busy making plans.

Chaos reigns in Skeldale House. Siegfried has the bright idea of bringing in an experienced bookkeeper, Miss Harbottle, to bring method to their madness. She's certainly efficient, but the cracks start to show and a sick ferret puts a spanner in the works.

Farmer Dakin is very attached to his injured, elderly cow, Blossom, but Siegfried advises letting her go. Having made a few rash decisions recently, he might have to put aside his pride as James presses him to see the truth of the situation he has created.

However misguided it might be, James and Helen take inspiration from Siegfried's "Carpe Diem" approach, and make a long-awaited decision.

It is Spring 1940, and without Tristan, Skeldale House is busier than ever. James and Helen dream about the future, hoping that he won't be called up. And a chance encounter with young lad, Wesley Binks, leaves James worrying if his dog, Duke, is being mistreated.