In a time not long from now, the veil between fantasy and reality is ripped asunder—creatures of myth and fairy tale spill into the mortal world. Enchanted yet horrified, humans force the magical beings Underground, to colonize the sewers and abandoned subway tunnels beneath their glittering cities.

But even magic folk cannot dwell in harmony, and soon two Worlds emerge: the Lightworld, home to faeries, dragons and dwarves; and the Darkworld, where vampires, werewolves, angels and demons lurk.

Now, in the dank and shadowy place between Lightworld and Darkworld, a transformation is about to begin....

Ayla, a half faery, half human assassin, is stalked by Malachi, a Death Angel tasked with harvesting mortal souls. They clash. Immortality evaporates, forging a bond neither may survive. And in the face of unbridled ambitions and untested loyalties, an ominous prophecy is revealed that will shake the Worlds.