Madison and Halle Wilde are sisters in high school on the day the world ends. A stone arch appears in the middle of downtown Austin, Texas and everything changes. Green mist oozes out of the arch and half the people in the world get sick with a high fever. The ones who get better wake up with strange marks on the back of their necks-marks that symbolize the awakening of magical powers in the person with the mark. Overnight, the world as we know it begins a slow slide into chaos and a race for survival begins. Madison knows that she and Halle are different, both of them waking up with dragon symbols on the back of their necks, a mark that no one else seems to have. Madison feels compelled to go to the arch in Austin, an arch that seems to be a portal to someplace else, a place full of sinister possibilities. But to do that, she will need to open six other magical gates, first. Each gate she opens releases dark and murderous things into the world, monstrous things that tend to eat people and these are the things that will lead Madison down a path she is not sure she wants to follow but may not be able to stop. Madison wants to make sure that whatever happens, she and her beloved sister are safe. Halle is blonde and clueless, more interested in the latest lip gloss than in world events, but Halle loves Madison more than anyone else and they have always been a team. As the mystery of the magical gates draws them in and they struggle to reach the arch, Madison begins to see something about her sister that bothers her. Halle has been gifted with powers of her own. Halle is the only other person with a dragon on her neck and Halle Wilde could be powerful enough to put an end to all of Madison's plans if she chooses to. Worse, Madison suspects she will have to break Halle's heart into a thousand pieces to open the final gate and this betrayal might destroy them both and take the whole world with them.