Rimfire the sixth book in the "Morgan Horse" series by Ellen Feld take s readers to a whole new realm within the world of horses. When Heather travels to Oklahoma to visit family friends she is introduced to Barrel Racing. Falling in love with this quick paced sport, Heather is thrilled when she returns home and discovers Rimfire, a fabulous Morgan barrel racer that just happens to be for sale. When her parents refuse to buy yet another horse, Heather convinces her friend Nicholas to purchase Rimfire. Every thing is going well until Heather decides to take Rimfire to a competition without Nicholas' permission. What will happen?