FOR CENTURIES, the world of Komos has been neatly divided into two categories: Light and Dark, the kingdom of Aether and, beyond the uncrossable border, the kingdom of Erebus. The relic of a great war headed by the royal Evenellis brothers, said to be the first humans blessed with the ability to cast magic, the division between the Light mage Aetherians and the Dark mage Erebusians has been heralded by a long and bloody history of hatred for one another on account of their magical differences.

            Sixteen-year-old Nerissa Smith and her younger brother, Poseidon, are Grey mages: a perfect and unheard of mix of Light and Dark. Just months after the Heavens have lost their regular hue to an extraordinary, omnipresent grey, Poseidon is dreaming of the angelic diviners described in myth books across the globe, and their secretive mother is acting even more oddly than usual. When her past unexpectedly collides with their present, the three of them are forced out of hiding and wind up under the protection of a dedicated group of political reformists. Led by a childhood friend of their mother’s, the idealistic ex-noble Adonis Archer, these people want a revolution—and they think Nerissa and Poseidon can be the ones to spark it.

            But it not only the social order of their kingdom that is falling out of balance; the infinite entity Chaos, giver of all the world’s magic and commander of the twelve mythical angels of Poseidon’s dreams, seems to have something to do with the disturbance of the Heavens. By virtue of their hybrid magic, it is suddenly up to Nerissa and Poseidon to find a way to restore stability to their world, even as they prepare for the war they were born to fight.