Neither dead nor alive, demons are rampant in Joseon. With his home country on the verge of collapse, Prince Ganglim returns to Joseon, only to be greeted with peasants who seem to be infected with a mysterious virus. He is forced to kill his own people alongside Baron Park and his men, and he unwillingly joins their crusade to eliminate all the demons before they reach the royal palace.

Meanwhile, Minister of War Kim Ja-joon has his eyes set on the throne and uses his authority and influence to gather enough support to dethrone the king and uses the virus to create chaos in the palace…

As the Prince pits himself against the unscrupulous Minster, an unbelievable bloody battle begins!