Böcker i Extra-serien

To protect their worlds, Olessia and Ryder must conquer the true enemy.The one that haunts them both.The one they see in the mirror.Ryder is human. Olessia is something else. At least, that is how it was to begin with. Now, the extraordinary secret that unites them could destroy the people and places they love. Running from an extraterrestrial ruler with a thirst for war, and the enemies who seek to use them to end his rule, the girls are forced onto very different paths. Isolated from each other and the strength their unity brings, Olessia and Ryder will have to confront their deepest fears alone.Because the power that haunts them, may be all that can save them.