First few pages: Little Red Riding Hood, except that the wolf is humanoid and in a fun/cute twist Red likes eating people too. 300 pages later: Tribal cultists consume each other and meld into an elritch mass of bodyparts made as a living chariot for the object of their worship, Red, while dark terrors pick at Wolf's mind and morph her into an ancient monster of prophecy.
Huh, this stops short of the ending. And the other comment has a point about how the mood changes dramatically later on. Anyway! Need to read this all soonish.