Red (The Circle Trilogy, Book 2) (The Books of History Chronicles)

In the second installment of Dekker's mind-bending trilogy, Thomas Hunter attempts to save two worlds from the evil he has unleashed. With the devastating realization that he has unleashed death into both worlds, he now must figure out how to undo this evil while trying to save his true love. From meeting with world powers in one world to leading a small band of mighty warriors in the great forests of the other world, Thomas is determined to change the history of two realities or sacrifice all in trying.