Following the conquest of Gojoseon by Han China in 108 BCE, the surviving tribes and city-states of Manchuria and the northern Korean Peninsula are harshly subjugated as tributaries to the Han, who are portrayed as ruling with an iron fist from the Four Commanderies. Haemosu, the leader of the local resistance in the form of the Damul Army, covertly teams up with Prince Geumwa of Buyeo to defend and rescue Gojoseon refugees throughout the land. After being injured in a battle, Haemosu is rescued by Lady Yuhwa of the Habaek tribe (to whom Geumwa has taken a fancy), and they fall in love. Haemosu is subsequently ambushed and captured by Han forces (and after falling off a cliff is presumed dead by the outside world), and the now-pregnant Lady Yuhwa is forced to seek shelter in Buyeo, where she becomes Geumwa's concubine and gives birth to Haemosu's son, Jumong. They maintain that Geumwa is Jumong's father, when in fact Haemosu is his father.