Carole Hanson writes a letter to the daughter of a Middle Eastern President inviting her to come riding at Pine Hollow. She hopes she might get a reply with an interesting stamp, instead she gets security guards roaming the grounds looking for spies. When a real spy shows up, it's the Saddle Club who rides to the rescue.
Lisa Atwood just cannot work up the nerve to tell her mother she really does not want to go to Wentworth Manor, especially after she wins a full scholarship, so her friends in the Saddle Club come up with a plan to make Mrs. Atwood have second thoughts about the fancy boarding school.
The Saddle Club members find themselves in over their heads when they take on too many projects at one time, but they promised to take care of a sick horse and find their friend a new horse to buy, and they are determined to accomplish both things; meanwhile, Stevie and her brothers call a truce in honor of their grandmother's visit.
The Saddle Club's friend from England, Lady Theresa, otherwise known as Tessa, is coming for a visit, which Veronica views as a chance for revenge against Tessa for snubbing Veronica when the Saddle Club was in England.
The Saddle Club girls are participating in a new kind of horseback activity, endurance riding. They will have to condition their horses and themselves if they plan to make it across the finish line, and also deal with an annoying rider named Chloe.
