Ohana: Book 2 of the Indigo Chronicles

In a sweeping panorama from the continent-spanning forests of Oz to the dystopian hell that is Pembroke, the Indigo tribe grows as they hire archaeologists to determine why their homeland of Oz is uninhabited. They uncover an ancient evil bent on destroying all other sentient life in the universe — one that exterminated cave men and other species on Oz. They also battle evil governments in other universes and establish themselves in a quaint but beautiful timeline.