Through Fire & Sea — Nicole Luiken

There is one True World, and then there are the four mirror worlds: fire, water, air, and stone. And each has a magic of its own...

In the Fire World, seventeen-year-old Leah is the illegitimate daughter of one of the realm's most powerful lords. She's hot-blooded -- able to communicate with the tempestuous volcano gods. But she has another gift...the ability to Call her twin "Otherselves" on other worlds. Holly resides in the Water World -- our world. When she's called by Leah from the Fire World, she nearly drowns. Suddenly the world Holly thought she knew is filled with secrets, magic...and deadly peril. For a malevolent force seeks to destroy the mirror worlds. And as Leah and Holly are swept up in the tides of chaos and danger, they have only one choice to save the mirror worlds -- to shatter every rule they've ever known...