I believe we are getting close to the reveal of Mu-deok's true identity. A significant part of the audience has finally figured it out (I'm basing this on Twitter and other message boards), so it's not going to be a big revelation to the audience - but it will be fun to watch the shock on the characters' faces! Not to mention "Naksu" who really doesn't like young Jin sister very much - in fact, I think they have upcoming scene sometime this weekend - one of the remaining ones from the 6 minute preview/trailer.
Something has always puzzled me and it is the description of Mother Jin (Ho-kyung).
Jin Ho-kyung - Jinyowon director, the head of the Jin family, who continues to inherit the maternal line. Behind her powerful charisma, she has affection for her eldest daughter, whom she lost when she was young. A first-time mother.
What is meant by "first-time mother".??? When the show began, I speculated that Eldest Daughter wasn't born a Jin but became a Jin when her father married into the Jin family. If that was the situation, she would be a step-daughter to Ho-kyung. [And Holy S**t what if Dad's original surname is Choi!!?? - okay, I digressed; my apologies; BUT. . . . What if?? ]
There are no other hints at this, but I hold that "first-time mother" in reserve to see if it means anything.
What happened to 10 (?) year old Bu-yeon? The story in my head is that she somehow got into Jinyowon, touched the Ice Stone (I don't think she swallowed it!), was blinded and Mom/Dad sent her away for "someone" to care for her - because a blind girl would not be able to be around magical artifacts, good or evil. That someone died and "blind girl" Mu-deok was "sold off". Dad's been in Sarin looking for her.
That's the story in my head. And I still want to know what is in Jin Bu-yeon's constellation plate.
Meanwhile, if they ever show what happened to 10 year old Jin Bu-yeon, I still think the child actress is going to be the same as the one on the boat with Master Lee.