(From what I can remember of the plot):
Main characters: female protagonist and her grandmother!.
Setting: Storm
Grandmother takes protagonist into wildlife preserve(!?) then the protagonist goes through a hole in the base of a very large redwood tree!. She travels back in time, but there are magical creatures there!. One detail I remember is that they passed a green, acidic looking pool of water on their way there and back in time it was clear until the protagonist had to throw some magic powder in it to escape enemies (weird magical creatures)!. Can anyone help me out here!?!?!?!?!?!?Www@QuestionHome@Com