Years ago, the Elantian colonizers invaded Lan's homeland and killed her mother in their search to uncover the Last Kingdom's greatest the location of its legendary four Demon Gods. Lan's mother devoted her life to destroying the Demon Gods, and Lan is determined to finish her mission. Yet, there are others searching for the gods, too.

Zen knew his soul was forfeit the moment he made a deal with the Demon God known as the Black Tortoise, but he's willing to lose himself if it means saving the Kingdom--and the girl--he loves. But to crush the colonizers who have invaded his land he needs more power than even a single Demon God can provide. He needs an army. And he knows exactly where he can find it--in the undead army his great grandfather lead decades ago.