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.