In the middle of the night, Anna hears Acorn's whinny in the Crandal paddock. There is a fire in Dr. Crandal's animal clinic. All the animals are in danger! The Pony Pals notice that a stray cat who was staying at the clinic is missing. Anna and Acorn are determined to find the stray. Can Acorn lead the Pony Pals to the cat?