"Out with the Old - In with the New" - Spoiled brat Veronica di Angelo got an expensive, perfect thoroughbred for Christmas. She hasn't given a backward glance to her other horse, Garnet. When Garnet is finally ridden by a nice girl who might want to buy her, the mare acts too frisky and looks unkept. The Saddle Club is determined to find a loving new home for the unloved horse. But the people who come to look at Garnet make the girls fear, she'll end up some place terrible. Despite their anxiety, Stevie, Carole and Lisa must bid farewell to one of their favourite horses. Carole must also say a special farewell: Her friend Cam is moving. It looks as if the Saddle Club is going to learn some hard new lessons about what it means to say good-bye. This story is about a special kind of swap. Lisa Atwood's visitor, Merrill, loves horses almost as much as The Saddle Club does. Lisa, Stevie Lake and Carole Hanson are happy to give Merrill a few pointers on her form over fences during their rides at Pine Hollow Stables. Then Merrill becomes convinced that she can ride only one horse.
When the Saddle Club learns that she wants to take a beloved stable horse home to Maine, they know they have to do something. The girls have already planned a birthday party - a Yankee Swap - for Merrill. Will a Yankee Swap of another kind persuade Merrill that she can ride any horse well, or is one of the Saddle Club's favourite horses leaving Pine Hollow for good?