This is the scene I was talking about!

From previous post: 

OH MY GOD REMEMBER WHEN HAESOO WAS UNCONSCIOUS (episode 6) AND SHE BEGAN THINKING OF KOREA'S HISTORY AND REMEMBERED THAT THE FOURTH KING KILLED HIS BROTHERS AND SUBJECTS!?!?!?

SPOILERS AHEAD (WELL SORTA)!!!!!!!!

DON'T LOOK UP GWANGJONG (KING'S NAME) AND DON'T LOOK UP IS ORIGINAL NAME AND OH MY GOD I'M FLIPPING MY !!!!!!!!!!!!!!!!!!!!