The Three Worlds — Nara Duffie

Lillian and her best friends, Katy and Maisy, barely survived their first adventure in the Monster Realm. Now they have only days to stop a war between the worlds, a war in which the mythical creatures of Lanodeka plan to reclaim the earth as their own.

But this time, the girls have to face more than dragons and griffins, sirens and elves, rocs and harpies. They discover the real power behind the war, a power that is using the Creation Stone to build an army unlike anything they could have imagined. Worlds are about to change.