Bingo.
Someone listen to this guy, please.
It was an abandoned quest idea. There is no answer to this mystery.
That's why people are so interested though, because it was abandoned and it clearly shows in the game. Heck, ALL the thieves in the cistern that aren't Bryn or Mercer have cut content that shows. It bothers me every time I go through the cistern and that one guys says "I was hoping we could talk, if you had a moment." or something like that.
I guess people just don't like being teased.