Dong Yi's Secret - S1.E34

Jang Hee Jae is summoned to meet Qing delegates who are angry about the fake security records. They warn him that the Crown Prince position can be reversed and if they don't get the book before they leave, the King will be informed. Jang Ok Jeong in the meantime wants to make Dong Yi an official concubine. The real reason is, Jang Ok Jeong wants to know about Dong Yi's past because the candidate's background will have to be thoroughly checked. Then, the King also asks Chief Seo to check Dong Yi's past. He also tells Chief Seo about the cliff and when he heard about it, he is very shocked.