Tragedy strikes Bill Shadwell when his herd of dairy shorthorns contracts Johne's disease. As Shadwell approaches retirement, his son is keen to move into more profitable Friesian dairy cattle -- a move which means both James and Siegfried are caught up in the family's battle of wills. Mr. Grimsdale's bull poses problems of a different kind when Siegfried is convinced it has swallowed a dangerous metal object. But tightfisted Grimsdale is not convinced that an operation is needed. Tristan's new metal detector could prove to be the solution to a tricky dilemma.

Queen Elizabeth II's Coronation is cause for Darrowby celebrations on a grand scale. James and Helen's 12-year-old daughter, Rosie, is due to be crowned, too -- as Darrowby's pageant princess -- by her reluctant elder brother, Jimmy. But a severe cough could put a fast end to her starring role in the festivities. Helen is keen to try Mrs. Alton's herbal remedy, but James tells her to give penicillin a chance first. Siegfried also resorts to traditional cures when he tackles a sheep with liver fluke, and is all too eager to pass on to James a rather smelly problem afflicting a dog called Wolfie.

There's unusual friction in the Herriot household when 12- year-old daughter Rosie announces that she wants to become a vet -- against her father's wishes. James goes out of his way to show her the arduous, dirty and dangerous side of his work, while Helen thinks he ought to encourage her. But treating her best friend's pony, which has tetanus, may prove too much even for the determined Rosie. Siegried, meanwhile, manages to lose Mrs. Pettinger's kitten Prudence, which escapes from the surgery and hitches a ride to Hull, causing consternation in Darrowby and mirth for Tristan.

It's raining cats - literally - when Tristan has to face the terrors of an enormous sow, Our Gracie, and her litter of piglets, who are due to be castrated. When the farm cats take a fancy to the anesthetic-stuffed offcuts, they start to doze off in some very unlikely places. Mrs. Clarke, a very determined old lady, is struggling to keep her farm running until she can hand it over to her young granddaughter, Mary. But she is reaching the stage when she can no longer handle the pressures, even with her elder granddaughter, Katherine to help -- and Katherine is planning to pursue a nursing career in Africa...