Haechi Season 1 Episode 15
A Chaotic Night
Chang Joong and Yi Gyeom meet the king to recommend Prince Yeoning as the Crown Prince. Meanwhile, Moon Soo and his colleagues notice that Yeo Ji isn't back after she left to talk to the students. It turns out the assassins sent to kill Prince Yeoning were ordered by Prince Milpoong and not Min Jin Heon. The widowed Queen recommends Prince Yeoning, and the king, after some doubt, orders Prince Yeoning be made Crown Prince.