Evening Star - Dragon Fire, #1

When an orphaned fourteen-year-old dragon, Star, returns home from hunting to find that his little sister, Sunny, has been captuerd by humans, he sets out to rescue her. With the help of his grandmother and Saffire, a dragon he meets on the way, Star tries to reach the mining Facility where captured dragons are kept as slaves. Meanwhile, Sunny figures out life in the Facility and begins to make new friends among the other captive dragons.
With the help of Iella, a human girl sympathetic to the dragons' plight, Star and Sunny make a plan of escape. Evening Star is juvenile fantasy fiction, aimed for kids fourth through sixth grade.