When Jimmy's Christening day is interrupted by the arrival of a surprise visitor, Siegfried makes a promise he struggles to keep, while a furry friend helps Helen to find common ground with James's mother.

Carmody gets outstanding exam results and is offered a position in a research program in London but he wants to turn it down so that he can stay at Skeldale where he can support the war efforts as a vet. Siegfried is relieved but worries that he might be holding Carmody back.

An exhilarated Mr Bosworth summons Mrs Hall to examine a piece of debris dropped from a plane into a remote field - this could be his hero moment. Doris arrives at the surgery with a poorly ferret for James to treat. Carmody finds himself oddly unable to string a sentence together in front of her.

Siegfried and Carmody meet the glamorous Miss Grantley and her herd of pygmy goats. Two are particularly hyper-sensitive and the vets must figure out the issue. There's a spark between Siegfried and Miss Grantley, who makes him realise that Carmody has to make the right decision about his future.

Meanwhile, what Bosworth thinks could be an explosive turns out to be something far less sinister. But Mrs Hall struggles with Mr Bosworth's overzealous reaction to the incident.

Siegfried encourages Carmody to take the offer but Carmody doesn't want to say goodbye to Skeldale. James treats Doris's ferret, and Helen realises that Doris's rat poison could have been behind a previous incident. Carmody finally makes a decision about his future and Mrs Hall and Bosworth mend their relationship.