Thirteen-year-old Janet Marshall spends all of her spare time daydreaming about horses. One night, she dreams to life a magical white mare, whom she names Storm. Astride her dream horse, she journeys deep into a wild canyon where she discovers the remote ranch that is the mare's home. But the dream becomes a nightmare when she discovers the truth: her horse is a darkly magical beast that can never be tamed. And the horse's owners are ghosts, doomed to relive the tragedy that has kept them trapped in time for more than a hundred years.