One twin sister was raised in the Supernatural world, confident and popular. The other was raised in the human world, an offbeat outsider. Now they're about to be reunited at the Supernatural Academy, and neither one of them is thrilled about it. Learning you've got a secret sister is hard enough, but then they find out the true reason their parents separated them at birth: they're Dragon Marked, cursed to serve the evil Dragon King. These adversarial twins will have to learn to get over their differences and trust each other in order to save themselves and save the world.