Angels aren't supposed to have twins. They are too powerful, the bond is too great. Neither Heaven nor Hell can keep them appart. Still, they grew up so differently. When James finds out he cannot turn into a demon without currupting his long-lost sister, he discovers that it will be harder than he thinks to break his polar opposite- who is in some ways, like him. She wishes him to be good, and became an angel again; he wishes for her to reign in Hell and be a greater demon with him. Who has the bigger will? Who will get what they want, the angelic sister, or the demoniac brother?