As the curtains rise on the fifth season of "All Creatures Great & Small," Helen Herriot (played by Rachel Shenton) and Audrey Hall (portrayed by Anna Madeley) prepare for a visit to Mr. Bosworth (Jeremy Swift). Meanwhile, at RAF Abingdon, amidst the bloom of Spring 1941, James Herriot (Nicholas Ralph) engages in animated conversation with Banerjee (Samir Mahat) and another gentleman, their discourse centered around the thrill of aviation. Elsewhere, Bosworth discusses his curated collections and the importance of Victory Gardens with Mrs. Pumphrey (Patricia Hodge). While Dot Fawcett (Caroline O’Neill) recuperates, her colleagues eagerly volunteer to lend a hand in tending to the lush green spaces. Bosworth mentions that they are still in search of diligent wardens to oversee blackout duties, and Mrs. Pumphrey shares that their first Land Girl has arrived safely, accompanied by Farmer Danby.
Following the conclusion of their meeting, Helen and Audrey find solace in conversing about Dot's recent surgery. Helen asserts to Audrey and Jimmy that the world must continue to turn, unaffected by the recent addition to their lives. That very evening, at their home, Siegfried Farnon (Samuel West) indulges in playful moments with Jimmy, while Richard Carmody (James Anthony-Rose), engrossed in training Hamish, declines their invitation. Richard praises Hamish's intellect, noting that his departure from his previous owner was met with sorrow.
Wing Commander Whitely (Simon Paisley Day) provides James and his companions with an update on the war's progression, revealing that all flight training schedules will be accelerated. He announces that the first long-distance mission to Scotland will commence that very night, including Herriot, Hibbert (Luke Hammond), and Banerjee among the participants. Helen confides in Audrey her intention to inquire after Dot in the morning. Siegfried learns of an urgent convening of the North Riding Veterinary Society, mandatory for all members, scheduled for 9 a.m. the following day. He admits that they are already stretched thin, merely managing to cover the farms' needs. Audrey suggests an alternative solution, just as James notices Banerjee's absence. He discovers Banerjee meticulously rechecking his calculations, haunted by self-doubt.
As they embark on a leisurely stroll, they bond over their shared experiences. James recounts his first calving experience, and Richard is encouraged to take on greater responsibilities. James and his comrades gear up for their flight. When asked if he's alright, James insists he is fine, only to collapse moments later. Upon regaining consciousness, Medical Officer Reid (Callum Coates) interviews him, suspecting familiarity with brucellosis due to James's prior treatment of an infected herd. James confirms this but stresses that there was no indication of his own infection. Reid warns him of potential recurring fevers and delirium, unable to predict when James might resume active service.
Helen visits Dot, who has undergone a hysterectomy, and Dot shares the medication that aids her in drifting into peaceful slumber, accompanied by her tiny Frisk, ensuring she is never alone. Siegfried commends Richard for his commendable performance during his first solo flight. Helen arrives with Jimmy, her attention momentarily diverted by a concerning call from RAF Abingdon, until James reassures her with his presence.
He unveils his diagnosis to her, while James harbors hope that he'll soon be back in the barracks, the next day. Later, Reid revisits James with the Wing Commander's verdict: he's deemed unfit to fly. Reid concedes that he can no longer be considered fully fit. Thus, James's flying career comes to a close. Reid clarifies that typically, this would mean transitioning to ground crew duties, but that's not a decision within his realm. James confides in Hibbert and Banerjee about his plight later. They've been assigned to Atkinson for a mission to Scotland that evening. They assure him that it's not his fault. Desperate, James attempts to persuade the Wing Commander to reconsider his stance. Instead, the Wing Commander suggests he takes up digging ditches. Dot brings Frisk, deceased overnight, to Richard, intending to bury him herself despite her recent surgery. Richard insists on taking care of it, entrusting it to Audrey, who mentions that Siegfried usually contacts Mallocks, the local abattoir. Richard vows to inform Siegfried, filling out the necessary paperwork.
Pumphrey arrives to lend a hand to Audrey and the team, ironing out a few wrinkles with Bosworth. Suddenly, she reveals that she's been asked to evacuate Pumphrey Manor as it's being requisitioned by the army for a convalescent hospital. They'll make do with the cozy cottage instead. A misunderstanding arises between Richard and Siegfried at the clinic when Frisk escapes his box. Their spat is interrupted by Audrey, who learns it was Dot's cat. Helen and Audrey eventually locate the feline. Meanwhile, James lends a hand in digging trenches. Later, he learns that the training mission came under Luftwaffe fire. Reid shares that the boys were shot down over the North Sea: Atkinson perished, Banerjee, though rescued from the wreckage, is severely injured, and Hibbert likely died instantly. James confronts Wing Commander Whitely, blaming him for sending them with an inexperienced pilot. The Wing Commander acknowledges the risks but stresses that he always strives to improve their odds, though it's not always possible. James calls Helen to update her on his current situation. She suggests they send him home if he's no longer flying. Audrey checks up on Helen later.
James discusses a heifer's calving with Mr. Edwards, who urges him to focus on his current duties. James assists the men trying to deliver the calves, requesting binder twine. Bert fetches it, and with James's guidance, they manage to safely deliver the calves by looping the twine over their fetlocks. James approaches the Wing Commander, expressing his desire to serve in any capacity. If he's no longer needed there, perhaps he can be more useful elsewhere. The Wing Commander hands him his discharge papers, acknowledging the scarcity of vets at present. Audrey inquiries about volunteering as a blackout warden with Bosworth, but he informs her that only male volunteers are accepted.
Pumphrey overhears their hushed conversation, her ears perking up at the mention of the Wrens. She interjects, reminiscing about the tenacity of the Wrens she once knew, women who never accepted defeat. Audrey confides in Bosworth, revealing her gender when she donned the uniform of the Wrens during the last war. Pumphrey, eager to sway Bosworth, earnestly advocates for Audrey to take on the role.
Meanwhile, Helen gleans from Dot that Frisk, the cat, has once again retreated beneath the sofa, motionless. With a heart heavy with concern, Helen detects a faint heartbeat and quickly rushes Frisk to Siegfried for assistance. Siegfried and Richard examine Frisk, puzzled by his eerie stillness, akin to being under anesthesia's influence. Dot mentions casually that Frisk has been licking her saucer lately. It dawns on them: Dot takes her medication with tea, and after consuming it, places the morphine-laden spoon in the saucer. Siegfried concludes that the cat, inadvertently ingesting the residue, has been under the influence of morphine.
James' return to Darrowby is met at the door by Hamish. He discovers Jimmy before Helen does, a tender reunion unfolding. Later, James is apprised of Frisk's morphine ordeal. In a surprise visit, Audrey appears in her Wrens uniform, her eyes sparkling with determination to contribute more to the war effort. Siegfried, heartened by her resolve, expresses his approval.
Later that evening, James engages Siegfried in a heartfelt conversation about flying, expressing gratitude for Siegfried's care for Helen and Jimmy during his absence. With a sense of closure, James ascends the stairs to join Helen, their reunion a warm beacon amidst the day's events.
