Yeon Gaesomun
Fearing that the general's power and influence are rapidly overtaking the throne's, Yeongnyu orders Yeon Gaesomun to oversee the construction of the defensive wall Cheolli Jangseong in a remote province, which would effectively exile him. In retaliation, Yeon Gaesomun and his co-conspirators plan a revolt; it fails because of Choong's intervention, but the crown prince becomes seriously injured after he falls off a poisoned horse. The king unexpectedly declares So-hee as his successor to the throne, dashing Jang's hopes and causing him to finally shift his allegiance to Yeon Gaesomun.