Sarah and the Dragon - David L. Brown - Bog

Sarah Johnson is an 18-year-old California girl on track to become a physician when she meets a mysterious "dragon" who saves her life after a tragic earthquake. The dragon reveals himself as an alien, marooned on earth for many centuries. He adopts her as his student and begins to teach her his ancient wisdom. But a terrible evil looms over the earth and only Sarah and her new friend can stand against it, using her new skills and the dragon's advanced technology.