The Missing Horse Mystery — Carolyn Keene

A SEARCH FOR A MISSING HORSE LEADS NANCY TO A DARK DISCOVERY!
Nancy's attending the Midwest Grand Prix Dressage Championships, where many of the world's best riders and finest horses compete. But more than blue ribbons is at stake. As Nancy quickly learns, these horses generate big money, turning a friendly competition into a very nasty business.
Discovering a fire in the stables, Nancy barely averts a terrible tragedy. But now she faces a new danger: a valuable horse has vanished, and it's up to Nancy to save it. She pursues the truth down a trail of greed, deception, and sinister secrets...only to find herself in jeopardy!