This story is a sequel to The Freeport Venture
Kukri Doo has a good life in Freeport. She's almost twelve, her parents are warm and loving, she has a big sister to look up to, and Sunset Shimmer--the very same magus the young changeling met on the Venture--might be taking her on as an apprentice soon.
But then her big sister comes home with word that one of her jobs has gone wrong, and now the entire family is in danger. And now something ancient and evil has started stalking Kukri in the night...