Comment by Lofty on Kim Rok Soo

@Lofty but the king told het only royals can read that book. He didn't say anything about the ring. Ohh. Remember that the king wanted to make another ring for her? So if those rings can be made that easy, it means there can be more people who can have that ring. So anyone who posses that ring can read the book, if they can get permission in the royal library. I still think it's related to the king's blood or maybe some particular type of magic only his bloodline can use? 

Sorry for the long comment. :'))