Mrs Hall's world is rocked by bad news. Meanwhile, Tristan is given a special wartime mission involving pigeons, and the house readies to celebrate Jimmy's birthday.

After receiving outstanding exam results, Carmody is offered a position in a research program in London, but he wants to stay at Skeldale. An exhilarated Mr Bosworth summons Mrs Hall to examine a piece of debris that has dropped from a plane into a remote field.

With World War II underway, Siegfried takes up the slack at the surgery. James faces an uncertain future when he is grounded at the RAF. Mrs Hall and Helen consider their contribution within the community, and Carmody is eager to step up.

James needs a crash course for fatherhood. Mrs Hall referees between Siegfried and her new boss, Mr Bosworth, as they fall out over some of Mr Bosworth's safety tactics. Helen is concerned about the influence of Jenny's new friend Doris.

Everyone is determined to make Jimmy’s christening day special, while Siegfried is unimpressed when called up to Biggins’ farm.

Tristan and Carmody can't see eye to eye, but a quest to Pumphrey Manor might just bring them together. Helen tries to support James when unresolved feelings resurface.

James starts to behave out of character while examining Tricki, and his health takes a turn for the worst. Meanwhile, Siegfried, needing an extra hand in Carmody's absence, recruits a reluctant Tristan to help.