When Katy, an unhappy foster child, daydreams of impressing popular Sandra Magill, she has no idea of the adventures in store! Sandra has her own pony, and rides him in shows, and when an unexpected stray horse arrives in her paddock she's only too pleased. But at the same time her new friend, Katy, has disappeared. Sandra and her friends set out to solve the mystery, never imagining that the answer is right under their noses!