Book 6 Storm and the Silver Bridle by Stacy Gregg

Issie's colt Storm is growing up fast and dark eyes are watching as she trains him. When Storm disappears in the middle of the night, Issie suspects that mysterious Francoise D'arth is invloved. Now Issie must travel to the other side of the world to rescue Storm. But can she outwit his kidnappers? And is she brave enough to compete in the ultimate race for the Silver Bridle.