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.