Here's What Happened to Tristan and When He Comes Back in 'All Creatures Great and Small'

Viewers said goodbye to Tristan Farnon (Callum Woodhouse) at the end of Season 3 of All Creatures Great and Small when he left to serve in the Royal Army Veterinary Corps during World War II. Season 3 wrapped up on Dec. 23, 2022, and when Season 4 aired from Oct. 5 to Dec. 21, 2023, Tristan's absence was a recurring theme, as he was still overseas fulfilling his duties as an army vet.

While Tristan was away, all the main cast returned for Season 4, with a few new additions, including Richard Carmody (James Anthony-Rose), who stepped in to help during Tristan's absence.

Season 5, which premiered on Jan. 12, 2025, promised a heartwarming reunion, with PBS teasing Tristan’s return. He's "back from his overseas service in the Royal Veterinary Corps — and sporting a very handsome new mustache." But the question remains: When exactly will Tristan reappear in the show?

Callum officially returns as Tristan in Season 5, Episode 3 of All Creatures Great and Small, titled "Homecoming," which aired on Jan. 26, 2025. The episode centers around Jimmy’s christening day and starts with a moment of tension when Mrs. Hall (Anna Madeley) receives a telegram addressed to Siegfried about Tristan. While it initially causes alarm, the message turns out to be good news — it’s word that Tristan is finally coming home.

Season 5, Episode 3 also explores the dynamic between Siegfried (Samuel West) and Tristan as Siegfried admits he might need his younger brother more than Tristan needs him.

After the christening, Siegfried reflects on the bittersweet reality of caring for a younger sibling, only to realize later in life that the roles have reversed. However, details about Tristan’s time away in Cairo, where he served during the war, suggest his experience wasn’t all cupcakes and rainbows — and he may need his big brother’s support more than either of them expected.

While Tristan’s return isn’t entirely a surprise — PBS had already teased details about Season 5, including both Tristan and James’s return and the circumstances surrounding it — we now know that Episode 3 is when he finally makes his on-screen comeback.

After Tristan's return in Season 5, Episode 3, he will remain a regular cast member for the rest of the season. Season 5 will follow the same format as previous seasons, running for seven episodes without interruptions. New episodes will air every Sunday at 9 p.m. ET, leading up to the finale on Feb. 23, 2025.

Episode 3, featuring Tristan’s return, aired on Jan. 26, while Episode 4, "Uninvited Guests," is set to air on Feb. 2. This episode will focus on Tristan’s first meeting with Carmody, which, according to TV Insider, doesn’t go as planned. Episode 6 is another that centers around Tristan, this time bringing his and Siegfried's relationship to center stage.