Tessa has spent the last four years enduring the cruelty of her supermodel stepsister, Blake, whose beauty, popularity, and arrogance have made her life miserable. But when fate forces the two girls to share a horse, Tessa finds herself trapped in close quarters with the very person she despises most. As tensions rise and their rivalry threatens to spiral out of control, unexpected challenges begin to expose secrets and emotions neither girl is prepared to face. Will Tessa finally stand up to Blake, or will this uneasy ride turn into another chapter of her torment?