Tam and her older sister Cynnie are spending the summer with their uncle in Vermont, which means riding lessons! Cynnie has worked hard at her horsemanship, and is rewarded with her own dressage horse. But Tam likes the older neglected and mistreated Merlin, once a champion jumper, but now a ruined "jump-shy" horse. She and the stable hand Steve concoct a plan to reteach Merlin how to jump again, so her uncle will buy him for her own.