The day Gem Echols killed someone changed everything, and not just because they’d been betrayed. After Zephyr kidnapped their parents, Gem was forced to use the Ouroboros knife to kill the God of Air, absorbing their power in the act.

While for any other god things might work out okay, the Magician—whose role is to maintain balance—having the power of another god has thrown everything into chaos. The Goddess of Death can now reanimate corpses; the God of Art's powers have become corrupted and twisted, giving life to his macabre creations; and, while the God of Land has always been able to communicate with creatures of the Earth, now everyone can hear their cries.

As Gem, Rory, and Enzo search for a way to restore the balance without sacrificing themselves, new horrors make them question how far they're willing to go. In the end, Gem may be forced to fully embrace their merciless nature and kill off their own humanity—if it ever really existed in the first place.