Haechi - Season 1 Episode 4 Welcome Back, Prince Yeoning!
Overview: Moon Soo finds out that the Roh Tae Pyeong he was chasing after was Prince Yeoning. Prince Yeoning decides to spread a rumor about Prince Milpoong and his evil deeds. The rumor eventually reaches the king and the royal court, and the king orders investigators to submit a detailed report. Yeo Ji realizes that she had acquired decisive evidence for where the body of Tae Pyeong is buried.