Tonton Streaming Jewel in the Crown (2010) S1E60 - A Happy Ending

Dong Yi leaves the palace and set up her own citizen's advice bureau to help lowborn who have problems with corrupt nobleman. Then, she discovers that the Finance Minister and Police Chief are involved in corruption and they also frame a lowborn for the murder of an official. But, thanks to her investigation, the framed lowborn are released and the corrupt officials are caught. A few years later, the King and Dong Yi are both dead. Dong Yi's son, who becomes the new King of Joseon, visits his mother's grave with Cheon Soo and promises to be a good King.