Sami's seizures are getting worse and the voice in her head--an entity she knows as Codex--wants her to do something crazy. Use the Keystone. But if it stops the seizures, is it really so crazy? Or is SHE crazy? The Keystone takes Sami to Yaris Theta, a world of stunning beauty, alien landscapes, and strange creatures; where races of fantasy and science fiction mingle, and the line between technology and magic is blurred. She's unprepared for the ordeals she faces, and she'll have to become tougher, smarter, and more adaptable in order to survive, drawing on strengths she didn't know she had. In the course of her travels, she'll learn of a bitter war between Codex's people, the immortal Lainians, and a cruel race of genetically modified shapeshifters known as Xedosians. She'll find herself in the middle of their conflict, and she may be the only one who can end the war and save the Lainians.