“Jem, remember who you is. You’ve waited your whole life for this!”
The Flame in the Mist by Kit Grindstaff is a pretty solid GU story, with a decently intelligent protagonist, wise guides and helpers, a nicely complicated set of adversary figures…. and the best part, a pair of golden-furred rats named Noodle and Pie. I couldn’t quite get over those names through the entire story, they are just too wonderful.
Jemma is the youngest child of the Agromond family, who rule their land with cruelty and darkness. She is about to turn 13 when her world is blown apart – she discovers she is not their child after all, and rebels against their evil ways. She flees the castle, with the help of servants and animals, and is accosted in the forest by the spirits of children the Agromonds have killed. They want her help, but she must save herself first.
Eventually, Jemma makes it through the perilous forest and is helped by her friend Digby. They set off to find her real parents, though she temporarily ends up having to rescue Digby before they can move on. Once with her birth family, Jemma’s full history and ancestry is revealed, and she begins to learn how to harness her innate magical abilities, for she is the answer to her whole country’s prayers.
Before she is ready, Jemma is forced to confront the Agromonds when she must rescue Digby’s siblings who have been stolen. She returns “home” and pretends she is on their side, but things fall apart and she is almost defeated. In the end, she must face off against the demon the Agromonds have been working for – alone, of course – and then with her companions’ help, take care of the rest of the family. Then she is able to release the spirits of the children, and dispel the evil Mist that had ruined the land.
Interesting in that the adversaries are her “parents” (distant parents, indeed), and that she feigns a conversion to the dark side the way some other Girls Underground actually succumb to it (Helena in Mirrormask, Lily in Legend).