Whisked to Oz by a Kansas twister, Amy Gumm discovers that the magical land has been destroyed by Dorothy's tyrannical rule, a situation that compels Amy to join an order of deposed magic-wielders who seek to put an end to Dorothy's reign.
Amy, continuing her efforts to free an oppressed Oz, discovers harrowing truths about her mission, Oz's past, and a growing danger that threatens her Kansas home.