The Books of Faerie: Molly's Story #4

They discover Queen Titania captured by Barbatos, who has a new "master" – a giant green frog-like creature that the demon is forcing the faeries to build a lake for. A disguised Auberon is one of the workforce, and he and Titania are singled out by Rose for execution: she is in fact a flitling grown to human size as punishment for leading her kind in a rebellion, something which she intends to do again once she has had her revenge. Molly foils her plans by convincing Barbatos' master to relinquish Twilight, which has transformed him from a common frog, leaving the demon powerless. He is returned to his imprisonment in the Dreaming, and the faeries freed. All that remains is for Twilight to choose a new master so that it can protect Faerie for all time: the stone chooses Molly, curing her numerous enchantments and returning her home to resume her normal life again . . . until Faerie has need of her.