The Darrowby Fair is here! James is excited to serve as the official veterinarian, but Tristan, Siegfried, and even Mrs. Hall, knowing what’s in store, are betting on how long into the day he lasts.
It doesn’t start off well. Asked to examine Jenny Alderson’s ferret, James is bit to bleeding. While his finger is bandaged, Helen tells him that a breeder is coming to the fair and she and her father are hoping to sell their bull to her. James promises to vouch for the bull’s health.
But he begins to think he should examine the bull first, given that he had to give it a testosterone shot at the Dobson farm. Tristan reinforces James’s doubt while also also attempting to ply him with beer, hoping to win the bet by getting James drunk. In return, James brings up Maggie, the bartender Tristan has been seeing, commenting about how things seem to be getting serious, making Tristan nervous. Before he can drink the beer, James is called away to examine a cow.
He then notices Dobson talking to Hugh and moves to ask Dobson if his cows are in calf after mating with the Alderson bull. If they are, that would assuage James’s concern over the bull’s health—but Dobson is cagey in his answers, and James is quickly pulled away by his duties.
James’s doubts are heightened when Hugh tells him that there’s a lot riding on the sale of the bull for the Aldersons. Don’t go looking for problems, he warns.
But James doesn’t even have the time to look for problems. He has to forbid a man from entering his dog into the show, as the dog has a temperature. Go home, he tells the man, but the man is stubborn.
Meanwhile, Siegfried has opened up the surgery for tours during the fair. Mrs. Hall’s friend Dorothy is in town and lends a hand with the guests. She offers to watch the surgery while everyone else tours the fair. When Siegfried returns first, he awkwardly chats with her and they soon establish a rapport that Tristan and Mrs. Hall witness when they return.
Tristan gives Siegfried a knowing look, which Siegfried deflects by bringing up Maggie. Tristan admits he’s afraid of things becoming serious with Maggie. Mrs. Hall warns him not to trifle with Maggie’s affection.
As Mrs. Hall and Dorothy enjoy the fair on Siegfried’s behest, Dorothy asks about Siegfried. Even though he was widowed four years ago, he acts like he’s still married. The remark causes Mrs. Hall’s face to drop, and Dorothy assures her friend that she was right to leave that “brute”—presumably her husband.
Siegfried sets off to amusedly watch James measure ponies for the show. Almost everyone tries to cheat to get their animal in an easier class. When one man shoves James and the others close in on him, James’s temper finally boils over. The situation is defused when Mrs. Hall runs up bearing the dog with the high temperature—it was hit by a large pumpkin knocked off a table and broke its leg. Its owner had refused to follow James’s orders and bring it home.
Siegfried makes Tristan examine the dog and help set its leg. As they work, Tristan tells Siegfried he should have asked Dorothy to dinner. They begin to fight, until Tristan says that he misses Siegfried’s late wife too.
Families assembled in the next room for the pet contest overhear the argument. James begins to judge the contest, and awards first prize to a goldfish, because its young owner knew a lot of facts about it.
After Tristan suggests that James simply lie about the Alderson bull in order to solve his dilemma, James finally goes to examine the animal. There is something wrong with it. Hugh asks him to keep that knowledge to himself, just for today, for Helen’s sake.
As the fair winds up, Mrs. Hall intervenes in a rigged game that people have been complaining about all day. She takes the game’s gun, fixes a switch on it, and fires cleanly, winning prizes for Jenny Alderson. Siegfried gives the sick dog, with a cast on its leg, back to its owner, who effusively thanks him. The dog is the man’s only company since his wife died. Tristan tries to end things with Maggie, and she easily accepts: they were never serious anyway.
The Aldersons and their potential buyer find James in the pub and ask him to vouch for the bull’s health. He turns attention on Dobson, asking if his cows are in calf. Finally, Dobson says he’s not sure. James tells the truth: the bull might be lame. So why wouldn’t Dobson answer? He looks at Hugh.
Hugh paid Dobson off without the Aldersons’ knowledge in order to get their bull sold—Hugh and Dobson knew there might be something wrong with the bull, but the Aldersons didn’t. Helen is furious at Hugh: he’s made her father look like a liar. But Hugh salvages his relationship by telling Helen he loves her and would do anything for her. They leave town together, to James’s disappointment.
Disgruntled fair attendees begin to heckle James for not allowing them to cheat. James lets loose: you should all be ashamed; I was just trying to be fair, he shouts. A villager comes over and congratulates him, buying him a drink. He’s finally being accepted in Darrowby.
And the bet? Mrs. Hall wins. She knew James would last the whole day.