Now that summer has arrived, Kate and Holly are off to Beaumont Park in England-home of rock-star horses, Olympic equestrians, and a private beach for the girls to ride on.Kate is excited about training with her idols. Holly is even more excited about making friends with a real-live princess and attending the London premiere of Moonlight. This is the stuff dreams are made of.But beneath the glossy surface lurks danger. After a quarrel with Kate, Holly storms off with the princess and lands in more trouble than she ever bargained for.