The Miller household is thrown into chaos when Ash's baby brother is born and Ash finds herself at the bottom of the pecking order for the first time in her life. The baby is cute, but very noisy! Ash finds solace at Shady trails Riding Ranch. It's every horse-mad kid's fantasy and Ash lands her first real job there. But as Shady trails grows, Shady Creek Riding Club starts to lose members, which is worrying for Becky, whose father runs the club. She presents Ash with an ultimatum: it's Shady trails or their friendship. Just when Ash is convinced that she and Becky will never rekindle their relationship, Becky arrives with devastating news. Her sister Rachael has sold the beloved Appaloosa mare Cassata and wants to use the money to buy an old car. the friends put aside their differences and determine to bring Cassata home - whatever the cost.