内容简介：
Peggy Clay, a fourteen-year-old Minnesota farm girl circa 1896, visits the circus and loves the dapple-gray performing horse, Jupiter. The young girl bears an uncanny resemblance to Lucy, the bareback rider. When Jake Parker, a handsome but evil roustabout, deliberately sets fire to the circus tents, everyone believes Lucy and Jupiter are lost. After awakening from an accident, Peggy has lost her memory and finds herself traveling with a gypsy who has mistaken her for Lucy. Their adventure takes them to Cody, Wyoming, where they meet up with Cooper, the previous owner of the circus, working in a wild west show, and are reunited with Jupiter. The conniving Lucy is in Wyoming with Jake, and the plot thickens when Lucy decides to switch roles with Peggy. Will Cooper and Jupiter come to Peggyas rescue in time to save her from their evil scheme?