The story follows three demon hunter brothers, after defeating what was thought to be the last demon. However, 7 years later, they are forced back into action after humans mysteriously start turning into demons.
In order to find out why his wife was killed, Chen Zheng, the general of Zhenhai, has been tracing a mermaid, but while doing so, he accidentally discovered a conspiracy in North Korea.
There are mysterious stories about royal hunters in northeast China, they live in deep mountains for generations to protect the dragon vein for royal families. A slain massacre happened in a remote mountain village and people asks the last royal hunter to find out the truth.
