Boober is afraid of catching The Pebble Pox. But when Wembley gets sick, Boober has to overcome his fear in order to take care of his friend.
Meanwhile, Doc tries to get Sprocket to go to the vet so that he can get his immunization shots.
The Pebble Pox is the most contagious of all Fraggle diseases. The symptoms in a severe case of the disease include fever, frizzy fur, ticklish teeth, aching tail, and an itchy, red rash appearing on the fur, not unlike measles, chicken pox, scarlet fever, or any human disease with a rash as a symptom.