All Creatures Great and Small season 6: all we know from Tristan's hidden trauma to cast and more

So far, Channel 5 have remained tight-lipped about what to expect from the upcoming season. 

Ahead of series five, Samuel West, who plays Siegfried, revealed that the cast were "about to have some discussions" about what season 6 would have in store. 

"One of the things that the books do is dramatise the fact that Tristan leaves," he told RadioTimes.com. "Brian, the original Tristan, left the practice. And I don't think we'll be doing that. I hope not. So at that point, I think we will be non-canonical."

Meanwhile, Callum Woodhouse confirmed that his character Tristan would be "another permanent fixture at Skeldale for a while". 

During an interview with HELLO! and other press ahead of the latest series, Samuel commented on Tristan's care-free attitude and suggested that hidden trauma could come to the surface. 

"Siegfried had a fairly terrible first war," explained the Slow Horses star. "He returned seeing terrible suffering, particularly to animals, and had friends in the profession who killed themselves many years later. 

"Tristan is all breeze and joy and drink and the club. I suspect that there must be something under that, but he won't talk about it, and it's a very interesting thing to play, because Callum is very good at that, and subtext is something that you know the series does well. So how well he really is, and how well he seems is to be discovered," he added. 

Callum later confirmed this, telling RadioTimes.com: "I definitely think he's seen some things that will probably stay with him."

He added: "I definitely think there's stuff he's probably not fully talked about, not fully expressed yet, which he was masking a lot of this series with drink and with jokes, which is obviously always Tristan’s way, but I'm sure more of that will get unpacked over time."

We'd expect to see all of the main cast members reprise their roles, including Nicholas Ralph as James Herriot, Rachel Shenton as Helen Herriot, Callum Woodhouse as Tristan Farnon, Samuel West as Siegfried Farnon and Anna Madeley as Mrs Hall. 

It's likely that Patricia Hodge will return as Mrs Pumphrey (alongside Derek the dog, who plays Tricki Woo), as well as Tony Pitts as Richard Alderson and Imogen Clawson as Jenny Alderson.

There's also Jeremy Swift, who joined the cast as Mr Bosworth in season five. With the war effort ongoing, it's possible that Jeremy could also return.

As for Richard Carmody (played by James Anthony-Rose), we expect we may have seen the last of him after the trainee vet was accepted onto a research programme at Imperial College London. But we won't rule out a return just yet!

In season five, James returned home from RAF training after being diagnosed with brucellosis, which made him unfit to serve. While he initially bottled up his emotions, the vet eventually opened up to Helen and revealed his devastation after his crew were shot down during a training exercise. 

Meanwhile, Mrs. Hall got stuck into the war effort by signing up as a black-out warden, Richard Carmody was offered a place in the research programme at Imperial College London and Siegfried was delighted to welcome his younger brother Tristan back to Darrowby. 

When Christmas rolled around, the Skeldale House gang celebrated Jimmy's first birthday while Mrs Hall learned the devastating news that her son Edward's ship, HMS Repulse, had been sunk by enemy fire off the east coast of Malaysia. The episode ended with a tear-jerking moment when Mrs Hall finally received a call from Edward to say that he was alive and well. 

Channel 5 has yet to announce a release date for season six and with filming only just begun, it could be a while until we find out more.

If previous seasons are anything to go by, we'd expect the new season to begin in September or October this year.