1937: James Herriot seizes an opportunity to interview for a job as a veterinary assistant in Yorkshire, in the magnificent rolling hills of the Dales. He meets Siegfried Farnon, his potential new boss who is idiosyncratic and chaotic, and his shrewd housekeeper Mrs. Hall. James is immediately thrown into the deep end when Siegfried takes him out to the local farms to put his skills to the test.

Just when James is settling into life in the Dales, Siegfried’s younger brother Tristan arrives, having passed his final exams at veterinary college and bringing his own unique brand of chaos to Skeldale House. Siegfried is delighted and instructs James to take Tristan on his rounds. James obliges but starts to feel threatened when Tristan goes out of his way to impress his brother.

It’s race weekend and Siegfried is interviewing for his dream job at Darrowby Racecourse. Tristan sets about collecting debts owed to the practice, but has to make a high risk bet to try and recoup his losses and save himself from Siegfried’s fury. James faces the toughest challenge of his career when he is called to treat Hugh Hulton’s pedigree racehorse, Andante.

Mrs. Pumphrey fears her beloved Tricki Woo is dying, so James takes Tricki back to Skeldale House for a period of rehabilitation. But things don’t go according to plan. Siegfried announces that Tristan isn’t going back to university until he can prove his commitment to being a vet, so Tristan must work to win his brother over. James gets closer to Helen when he helps treat their prize bull.

James has been named Attending Vet at the town fair. Siegfried and Tristan place a bet with Mrs. Hall to see if James will stick it out to the bitter end. James is pulled in all directions as ambitious locals try to cheat and bribe him to help them win. The Aldersons are hoping to sell their prize-winning bull and Hugh tries his best to support Helen. James is faced with an unenviable dilemma.

The Dales are in the grip of a bitter winter. Siegfried has flu and James’s workload has doubled. James and Tristan must decide if they should try out an extremely high-risk procedure against Siegfried’s advice. Mrs. Hall discovers it’s James’s birthday and Tristan sets about planning a surprise party. A surprise announcement in the Drovers brings James’s birthday to a difficult close.