A long but well-peopled fantasy with a strong environmental message. When Kate, 13, tries to help stop a group of unemployed Oregon loggers from cutting a unique stand of redwoods, she's cast back five centuries and propelled into the struggle against Gashra, a megalomaniac volcano creature with a very real scorched earth policy.'' The strongest feature of this novel is not the wandering, predictable plot but the colorful cast, especially the nonhumans-...