The action story of a hero named Lee Chung (Hyun Bin) who fights against "Night Demons" to save the Joseon nation. Lee Chung is the son of the king, and the greatest martial artist in the world. Although he is given to the Qing empire as a political hostage, he returns home upon hearing that his brother, the Crown Prince Lee Young (Kim Tae-woo (actor)), has taken his own life. With the nightmarish monsters plaguing the country and the minister of military Kim Ja-joon (Jang Dong-gun) plotting to overthrow the dynasty, Prince Lee Chung (Hyun Bin) will be fighting them alongside archer Deok-hee (Lee Sun-bin (actress)) and others.