Sometimes the hard part isn't falling off—it's getting back on. Thirteen-year-old Sienna Carson is spending the summer with her distant relatives at Hartwell Creek Stable while her parents settle a messy divorce. There she meets Dreamer, a fiesty, difficult Anglo-Arab. The beautiful bay gelding is hard to handle and, after throwing too many riders off, is at risk of being sent away. But as Sienna begins to form a relationship with Dreamer, she becomes convinced that he's not awful, just broken, like her ... and maybe, if both of them let their walls down, they could help fix each other.