For her, it's her late grandma's legacy. For him, the mother of all black arts spoils, granting one demon the power of a God. Immortality.
When occult-magnet Ruby falls victim to Demon Lord Drayvex's viperous allure, she loses a sentient dark relic to his light fingers and appetite for power. Like calls to like. But when Drayvex himself loses the relic to a traitor to the throne, Ruby coerces him - the tyrant king with a soft spot for humanity - into helping her save her pokey old world village from becoming a ground zero of mass demonic carnage.
Both invested in reclaiming the relic, the one thing Ruby and Drayvex agree on is that it's in the wrong hands. Co-existing in a precarious arrangement between predator and prey, to save the planet they both love for different reasons, they must become a formidable double-team in the face of an apocalyptic takeover. Now, the fate of both human and demon alike rests with a killer that walks between worlds, and a woman with a curse in her bloodline.