When Liv Winchester rides her beloved horse, Cactus Jack, to investigate, she is chased by strangers on an ATV. Later, while nursing an injured Cactus Jack in the barn through the night, she hears intruders. The mystery only becomes more frightening when Liv and her twin sister, Sophie, discover their grandfather's favorite stallion, Diego, is missing - along with Shane, the ranch hand on whom they both have a serious crush.