The gods play havoc with our souls. Callie: I'm torn in two. The mark of the gods has bound me to my mortal enemy, and not even the most desperate yearnings of my heart can break this tie. Between the slayer's vow and the cruel tricks of Idun, my free will has been stolen from me. All I can hope for now, is that my sister and I can find a path to salvation, but it feels as though we're...