From the introduction: Welcome to Korea. It’s not the Korea you are familiar with but it is close enough to the reality for many people. Not so for those who are a part of the Abyss. The Abyss is the generic term for the secret supernatural world hidden from the eyes of normal humans. Within the Abyss, magic is real, as are ancient clans of supernaturally empowered martial artists, and cults devoted to the exploitation of life for the sake of profit.