Penny Thompson was a girl with a ponytail and a taste for carrots, and, when this story begins, she was being held late after her first day in a new school because she had misplaced her identity and whinnied during class. But the incident is not exploited for its humor, just seriously approached as a childish misdemeanor. And all the incidents in the book are just as unconvincingly and stolidly handled. Penny and her friends think they see the ghost horse of a local legend, but it's no surprise when eventually they discover they'd sighted a guest of a costume party. Penny joins a horsemanship class, but there is less description of the horses than there is of the personal relations at the class--mainly a feud between an unsympathetic instructor and his ex-girl friend, who is agonized because diabetes keeps her from riding. Not much about horses or mystery in this story, which leaves it with very poor characters grazing in an incoherent plot.